Monday

December 5, 2016
Total # Posts: 2,279

**Maths**

You must find the least common multiple (LCM) of the positive integers 2 to 10 One way to find LCM's is to use prime factorization: 2 is prime 3 is prime 4 = 2 * 2 = 2 ^ 2 5 is prime 6 = 2 * 3 7 is prime 8 = 2 * 2 * 2 = 2 ^ 3 9 = 3 * 3 = 3 ^ 2 10 = 2 * 5 The LCM of all of ...

*December 5, 2016*

**Maths**

a5 = 3 a2 a12 = 2 a6 + 1 For AP: an = a1 + ( n - 1 ) d a1 = initial term of an arithmetic progression d = common difference of successive members a2 = a1 + ( 2 - 1 ) d a2 = a1 + 1 * d a2 = a1 + d a5 = a1 + ( 5 - 1 ) d a5 = a1 + 4 d a6 = a1 + ( 6 - 1 ) d a6 = a1 + 5 d a12 = a1...

*December 5, 2016*

**Math**

LCM ( Least Common Multiple ) for 8 and 20 = 40 a. 4 / 20 = 4 * 2 / 20 * 2 = 8 / 40 7 / 8 = 7 * 5 / 8 * 5 = 35 /40 Abigail collected more aluminum. b. 8 / 40 + 35 / 40 = 43 / 40 = ( 40 + 3 ) / 40 = 40 / 40 + 3 / 40 = 1 + 3 / 40 = 1.075lb

*December 2, 2016*

**Algebra 2**

A quadratic equation have the standrad form: a x ^ 2 + b x + c R = 290 x ? 0.2 x ^ 2 is quadratic equation: R = ? 0.2 x ^ 2 + 290 x + 0 The vertex of a quadratic parabola is the highest or lowest point, the maximum or minimum. When a < 0 a quadratic parabola has a maximum. ...

*December 2, 2016*

**Math**

n = 1 Denominator = 2 = 2 * 1 n = 2 Denominator = 4 = 2 * 2 n = 3 Denominator = 6 = 2 * 3 n = 4 Denominator = 8 = 2 * 4 n = 5 Denominator = 10 = 2 * 5 Expression for the n-th term: 1 / 2n

*December 2, 2016*

**Math**

The product of two prime numbers is NEVER a prime number becouse that it is a product and therefore has factors.

*December 2, 2016*

**mathematics**

315° = 360° - 45° cos 315° = cos ( 360° - 45° ) cos ( A - B ) = sin A * sin B + cos A * cos B In this case: A = 360° , B = 45° sin A = sin 360° = 0 cos A = 1 sin B = sin 45° = sqroot ( 2 ) / 2 cos B = cos 45° = sqroot ( 2 ) / 2 cos...

*December 1, 2016*

**Algebra**

x = Your number The difference between 5 times a number and 20 equals the sum of the number and 40 mean: 5 x - 20 = x + 40 5 x - 20 = x + 40 Subtract x to both sides 5x - 20 - x = x + 40 - x 4 x - 20 = 40 Add 20 to both sides 4 x - 20 + 20 = 40 + 20 4 x = 60 Divide both sides ...

*December 1, 2016*

**Math**

b = number of boys g = number of girls At first the ratio of the number of boys to the number of girls in a Mathematics Club was 1 : 2 b / g = 1 / 2 When 5 more boys joined the club , the ratio became 3 : 4 ( b + 5 ) / g = 3 / 4 b / g = 1 / 2 Multiply both sides by 2 2 b / g...

*December 1, 2016*

**math**

h = the height of the flagpole Proportion of the shadows: 4 / 1.5 = 12 / h 4 / 1.5 = 12 / h Multiply both sides by h 4 h / 1.5 = 12 Multiply both sides by 1.5 4 h = 12 * 1.5 4 h = 18 Divide both sides by 4 h = 18 / 4 h = 2 * 9 / 2 * 2 h = 9 / 2 = 4.5 m

*December 1, 2016*

**Math**

( x - 3.15 ) ^ 2 = x ^ 2 - 2 * x * 3.15 + 3.15 ^ 2 = x ^ 2 - 6.3 x + 9.9225 ( x - 3.15 ) ^ 2 = 4 p ( y - 219.7981936 ) x ^ 2 - 6.3 x + 9.9225 = 4 p ( y - 219.7981936 ) Divide both sides by 4 x ^ 2 / 4 - 6.3 x / 4 + 9.9225 / 4 = p ( y - 219.7981936 ) 0.25 x ^ 2 - 1.575 x + 2,...

*December 1, 2016*

**Math**

8 / 12 = 4 * 2 / 4 * 3 = 2 / 3

*December 1, 2016*

**Mathematics**

For the AP: 2 x = 8 + d 2 y = 2 x + d = 8 + d + d = 8 + 2 d 2 y = 8 + 2 d For the GP: 2 y = 36 / q 2 x = 2 y / q = ( 36 / q ) / q = 36 / q ^ 2 So: 2 x = 2 x 8 + d = 36 / q ^ 2 2 y = 2 y 8 + 2 d = 36 / q Now you must solve system: 8 + d = 36 / q ^ 2 8 + 2 d = 36 / q 8 + 2 d = ...

*November 24, 2016*

**f math**

Correction. On interval 0 ? x ? 270° sin x = 0 only for x = 0 and x = 180°

*November 20, 2016*

**f math**

1 - cos ^ 2 x = sin ^ 2 x 1 - cos ^ 2 x = 0 mean: sin ^ 2 x = 0 take square root of both sides: sin x = 0 On interval 0 ? x ? 270° sin x = 0 only for x = 0

*November 20, 2016*

**Pre-calculus**

Use trigonometric identities: sin ( x + y ) = sin x cos y + cos x sin y sin ( x - y ) = sin x cos y - cos x sin y cos ( x + y ) = cos x cos y - sin x sin y cos ( x - y ) = sin x sin y + cos x cos y sin ( x + y ) + sin ( x - y ) = sin x cos y + cos x sin y + sin x cos y - cos x...

*November 19, 2016*

**Math**

A woman is twice as old as her daughter mean: W = 2 D Five years ago wooman was W - 5 yrs , daughter was D - 5 yrs Five years ago the sum of their age was 62 mean: W - 5 + D - 5 = 62 W - 10 + D = 62 Add 10 to both sides W - 10 + D + 10 = 62 + 10 W + D = 72 Replace : W = 2 D in...

*November 19, 2016*

**Algebra**

Write your equation in explicit form: y = m x + n where: m is the slope of the line n is the y intercept 9 x + 3 y = - 22 Subtract 9 x to both sides 9 x + 3 y - 9 x = - 22 - 9 x 3 y = - 9 x - 22 Divide both sides by 3 y = - 9 x / 3 - 22 / 3 y = - 3 x - 22 / 3 Parallel lines ...

*November 15, 2016*

**maths**

Rearange your equations. 3 x - 2 y = 1 Multiply both sides by 2 6 x - 4 y = 2 2x + y = - 4 Multiply both sides by 3 6 x + 3 y = - 12 6 x - 4 y = 2 - 6 x + 3 y = - 12 ______________ 6 x - 6 x - 4 y - 3 y = 2 - ( - 12 ) 0 - 7 y = 2 + 12 - 7 y = 14 Divide both sides by - 7 y = 14...

*November 11, 2016*

**Math**

So what?

*November 11, 2016*

**math**

1. 2 / 5 = 2 * 2 / ( 5 * 2 ) = 4 / 10 4 2/5 = 4 + 2 / 5 = 4 + 4 / 10 = 4 * 10 / 10 + 4 / 10 = 40 / 10 + 4 / 10 = 44 / 10 1 7/10 = 1 + 7 / 10 = 10 / 10 + 7 / 10 = 17 / 10 4 2/5 - 1 7/10 = 44 / 10 - 17 / 10 = 27 /10 = 20 / 10 + 7 / 10 = 2 7/10 2. 5 2/3 = 5 + 2 / 3 = 5 * 3 / 3 + ...

*November 11, 2016*

**math**

( m n ) ^ 5 = m ^ 5 * n ^ 5

*November 11, 2016*

**math**

A student has passed 60 percent of the 20 quizzes he has written so far successfully mean: successfully quizzes = 60 % of 20 quizzes = ( 60 / 100 ) * 20 = 60 * 20 / 100 = 1200 / 100 = 12 The remaining quizzes = 50 - 20 = 30 quizzes 80 percent of the remaining quizzes ...

*November 11, 2016*

**math**

M = Mimi’s cd’s R = Rita’s cd’s The ratio of the number of Mimi’s Eminem cd’s to the number of Rita’s Eminem cd’s is 5:8 mean: M / R = 5 / 8 Rita has 18 more Eminem cd’s than Mimi mean: R = M + 18 Now you have system of 2 equations ...

*November 11, 2016*

**math**

You can represent your number like: x = 10 * a + b where: a = tens digit b = ones digit Two of my divisor are 8 and 12 mean you must find least common multiple of 8 and 12 Least Common Multiple ( 8 , 12 )= 24 This mean x = 24 b = 2 , a = 4 Proof: x = 10 b + a = 24 x = 10 b + a...

*November 11, 2016*

**Calculus**

f(x) is concave up on an interval if f"(x) > 0 In this case f"(x)= 2 So x^2-3 is concave up for all vales of x, including interval ( -1, 1 )

*November 11, 2016*

**Maths**

Length of the diagonal of a square: d = sqroot ( a^ 2 + a ^ 2 ) = sqroot ( 2 a ^ 2 ) = sqroot ( 2 ) * a The area of a square is A = a ^ 2 So a = sqroot ( A ) 1 hectare = 10,000 m ^ 2 0.5 hectare = 5,000 m ^ 2 a = sqroot ( A ) = sqroot ( 5,000 ) = sqroot ( 50 * 100 ) = sqroot...

*November 11, 2016*

**mth/208**

d = a b c Divide both sides with b c d / b c = a a = d / b c Your answer is correct.

*November 11, 2016*

**Geometrical progration**

a1 = initial value r = common ratio = 10 The n-th term of a geometric sequence: an = a1 * r ^ ( n - 1 ) In this case: a6 = a1 * r ^ 5 2,000 = a1 * 10 ^ 5 2,000 = 100,000 a1 Divide both sides by 100,000 2,000 / 100,000 = a1 0.02 = a1 a1 = 0.02

*November 11, 2016*

**Math**

5 1/2 = 5 + 1 / 2 = 10 / 2 + 1 / 2 = 11 / 2 2 1/3 = 2 + 1 / 3 = 6 / 3 + 1 / 3 = 7 / 3 5 1/2 /2 1/3 = ( 11 / 2 ) / ( 7 / 3 ) = 11 * 3 / 2 * 7 = 33 / 14 33 / 14 = 28 / 14 + 5 / 14 = 2 + 5 / 14 = 2 5/14 Average number of pages = 33 / 14 = 2 5/14

*November 11, 2016*

**Algebra**

You're welcome

*November 4, 2016*

**Algebra**

- 2 / 5 x - 9 < 9 / 10 Add 9 to both sides - 2 / 5 x - 9 + 9 < 9 / 10 + 9 - 2 / 5 x < 9 / 10 + 90 / 10 - 2 / 5 x < 99 / 10 Multiply both sides by 5 - 2 x < 99 * 5 / 10 - 2 x < 99 * 5 / 2 * 5 - 2 x < 99 / 2 Divide both sides by - 2 When we multiply or ...

*November 4, 2016*

**algebra**

Put x coordinate into equation: 3 x - 2 y = 12 and check y coordinate 1. For x = 2 3 x - 2 y = 3 * 2 - 2 y = 12 6 - 2 y = 12 Subtact 6 to both sides 6 - 2 y - 6 = 12 - 6 - 2 y = 6 Divide both sides by - 2 y = 6 / - 2 y = - 3 x = 2 , y = - 3 True 2. For x = 4 3 x - 2 y = 3 * 4...

*November 3, 2016*

**Algebra**

Remark: 1 1/4 = 1 2/8 ___________ 1, 1 1/8, 1 1/4, 1 3/8 1 1/8 - 1 = 1/8 1 1/4 - 1 1/8 = 1 2/8 - 1 1/8 = 1/8 1 3/8 - 1 1/4 = 1 3/8 - 1 2/8 = 1/8 Common difference = 1/8 Answer C

*October 28, 2016*

**Calculus**

Using the chain rule: u = 3 x du = 3 dx Divide both sides by 3 du / 3 = dx dx = du / 3 d cosh ( 3 x ) / dx = d cosh ( u ) / ( du / 3 ) = 3 d cosh ( u ) / du d cosh ( u ) / du = sinh u so d cosh ( 3 x ) / dx = 3 d cosh ( u ) / du = 3 sinh u = 3 sinh ( 3 x )

*October 28, 2016*

**Math**

n = the numerator d = the denomenator the fraction = n / d If one be added to the numerator of a fraction it reduces to 1 / 5 mean: ( n + 1 ) / d = 1 / 5 If one be taken from the denomenator it reduces to 1 / 7 mean: n / ( d - 1 ) = 1 / 7 Now: ( n + 1 ) / d = 1 / 5 Multiply ...

*October 28, 2016*

**MATHS URGENT**

ln ( x ^ 4) = 4 ln x 9 / ln x + ln ( x ^ 4 ) = - 12 9 / u + 4 u = - 12 Multiply both sides by u 9 u / u + 4 u * u = ( - 12 ) * u 9 + 4 u ^ 2 = - 12 u Add 12 u to both sides 9 + 4 u ^ 2 + 12 u = - 12 u + 12 u 4 u ^ 2 + 12 u + 9 = 0 Now, find discriminant using formula D = b ^ 2...

*October 28, 2016*

**MATHS URGENT**

7 ^ ( 2 x - 1 ) = 7 ^ ( 2 x ) / 7 ^ 1 = ( 7 ^ x ) ^ 2 / 7 7 ^ ( x - 1 ) = 7 ^ x / 7 ^ 1 = 7 ^ x / 7 7 ^ ( 2 x -1 ) + 4 * 7 ^ ( x - 1 ) - 1 / 14 = 0 ( 7 ^ x ) ^ 2 / 7 + 4 * 7 ^ x / 7 - 1 / 14 = 0 Make the substitution u = 7 ^ x u ^ 2 / 7 + 4 u / 7 - 1 / 14 = 0 Multiply both ...

*October 28, 2016*

**Math (Derivative)**

In your homework you can replace ∆h with h Is all the same.

*October 28, 2016*

**Math (Derivative)**

f´(x)= lim [ f ( x + ∆h ) - f ( x ) ] / ∆h ∆h-> 0 In this case : f ( x ) = 1 + 1 / x ^ 2 f ( x + ∆h ) = 1 + 1 / ( x + ∆h ) ^ 2 f ( x + ∆h ) - f ( x ) = 1 + 1 / ( x + ∆h ) ^ 2 - ( 1 + 1 / x ^ 2 ) = 1 + 1 / ( x + ∆h ) ^ 2...

*October 28, 2016*

**Maths**

a ^ ( n - m ) = a ^ n / a ^ m 7 ^ ( x - 1 ) = 7 ^ x / 7 ^ 1 = 7 ^ x / 7 7 ^ x = u so 7 ^ x / 7 = u / 7 ( a ^ m ) ^ n = a ^ ( m * n ) 7 ^ 2 x = ( 7 ^ x ) ^ 2 Again: a ^ ( n - m ) = a ^ n / a ^ m so 7 ^ ( 2 x - 1 ) = 7 ^ 2 x / 7 ^ 1 = 7 ^ 2 x / 7 = ( 7 ^ x ) ^ 2 / 7 = u ^ 2 / 7

*October 26, 2016*

**math**

Factor 8454 8454 = 2 * 3 * 1409 8454 = 6 * 1409 8454 / 6 = 1409 Remark: 2 , 3 , 1409 is prime mumbers

*October 24, 2016*

**Math**

( 5 x - 1 ) / ( 2 x + 3 ) = 4 / 5 Multiply both sides by 5 5 ( 5 x - 1 ) / ( 2 x + 3 ) = 4 Multiply both sides by ( 2 x + 3 ) 5 ( 5 x - 1 ) = 4 ( 2 x + 3 ) 5 x * 5 - 1 * 5 ) = 2 x * 4 + 3 * 4 25 x - 5 = 8 x + 12 Add 5 to both sides 25 x - 5 + 5 = 8 x + 12 + 5 25 x = 8 x + 17 ...

*October 24, 2016*

**Algebra**

( a ) Put t = 8 in your formula h(8) = − 4.9 * 8 ^ 2 + 70 * 8 + 30 h(8) = − 4.9 * 64 + 560 + 30 h(8) = − 4.9 * 64 + 560 + 30 h(8) = − 313.6 + 590 h(8) = 276.4 ( b ) Put t = 0 in your formula h(0) = − 4.9 * 0 ^ 2 + 70 * 0 + 30 h(0) = − 4.9 * ...

*October 24, 2016*

**Math**

a = first number b = second number The sum of two numbers is 21 mean: a + b = 21 Five times the first number added to 2 times the second number is 66 mean: 5 a + 2 b = 66 a + b = 21 Subtract a to both sides a + b - a = 21 - a b = 21 - a Replace this value in equation: 5 a + 2 ...

*October 20, 2016*

**math**

One third of them were men: 1 / 3 * 450 = 450 / 3 = 150 men Two fifth of them were women: 2 / 5 * 450 = 2 * 450 / 5 = 900 / 5 = 180 women One tenth of them were boys: 1 / 10 = 450 / 10 = 45 boys 150 + 180 + 45 = 375 450 - 375 = 75 girls

*October 19, 2016*

**Math**

1 / 50 = 1 * 2 / 50 * 2 = 2 /100 = 0.02

*October 18, 2016*

**Differentiation**

Use chain rule: dy / dx = ( dy / du ) * ( du / dx ) u = log x y = log ( log x ) = log u dy / du = d ( log u ) / du = 1 / u = 1 / log x ( du / dx ) = d ( log x ) / dx = 1 / x dy / dx = ( dy / du ) * ( du / dx ) = ( 1 / log x ) * ( 1 / x ) = 1 / x log x

*October 18, 2016*

**Geometric progression**

s2 = s1 * q s4 = s1 * q ^ 3 8 = s1 * q 40 = s1 * q ^ 3 s1 * q ^ 3 = s1 * q * q ^ 2 40 = s1 * q ^ 3 = ( s1 * q ) * q ^ 2 = 8 * q ^ 2 40 = 8 * q ^ 2 40 / 8 = q ^ 2 5 = q ^ 2 q = ± sqrt ( 5 ) You can construct two g.p. 1. 8 = s1 * g 8 = s1 / sqrt ( 5 ) s1 = 8 / sqrt ( 5 ) ...

*October 18, 2016*

**math**

x = larger number 45 / x = 3 / 5 Multiply both sides by 5 45 * 5 / x = 3 225 / x = 3 Multiply both sides by x 225 = 3 x Divide both sides by 3 225 / 3 = x 75 = x x = 75 Proof: 45 / 75 = ( 3 * 15 ) / ( 5 * 15 ) = 3 / 5

*October 18, 2016*

**math**

- ( 2x + 7 ) = - 2 x - 7

*October 18, 2016*

**math**

1) 11 x + 2 y - 4 x - y = ( 11 x - 4 x ) + ( 2 y - y ) = 7 x + y 2) 9 x + 2y - 5 x = ( 9 x - 5 x ) + 2 y = 4 x + 2 y

*October 18, 2016*

**algebra**

OR 17, 20, 23, 26 is an arithmetic progression. If the initial term of an arithmetic progression is a1 and the common difference of successive members is d, then the nth term of the sequence: an = a1 + ( n - 1 ) * d In this case the initial term a1 = 17, the common difference ...

*October 17, 2016*

**algebra**

n = 1, a1 = 17 = 3 * 1 + 14 = 3 + 14 n = 2, a2 = 20 = 3 * 2 + 14 = 6 + 14 n = 3 , a3 = 23 = 3 * 3 + 14 = 9 + 14 n = 4 , a4 = 26 = 3 * 4 + 14 = 12 + 14 an = 3 n + 14

*October 17, 2016*

**Algebra**

a = first number b = second number The sum of two numbers is 6 mean: a + b = 6 One number is 2 times the other mean: a = 2 b Replace a = 2 b in equation: a + b = 6 2 b + b = 6 3 b = 6 Divide both sides by 3 b = 6 / 3 = 2 a = 2 b = 2 * 2 = 4 a = 4 and b = 2

*October 17, 2016*

**algebra 1**

10 - ( s + 3 ) < 20 10 - s - 3 < 20 7 - s < 20 Subtract 7 to both sides 7 - s - 7 < 20 - 7 - s < 13 Multiply both sides by - 1 If you multiplied or divided both sides of an inequality by the negative number, then you must reverse the inequality sign. s > - 13

*October 17, 2016*

**Math**

9 / 8.1 = 5 / x Multiply both sides by x 9 x / 8.1 = 5 Multiply both sides by 8.1 9 x = 5 * 8.1 9 x = 40.5 Divide both sides by 9 x = 40.5 / 9 x = 4.5 5 apples cost $4.5

*October 17, 2016*

**Math**

1 / 2 = 1 * 3 / 2 * 3 = 3 / 6 - 1 / 2 = - 3 / 6 1 / 3 = 1 * 2 / 3 * 2 = 2 / 6 - 1 / 2 + 1 / 3 = - 3 / 6 + 2 / 6 = - 1 / 6 Answer A I don't know what3 5/1 nean. 5 / 8 - ( - 2 / 8 ) = 5 / 8 + 2 / 8 )= 7 / 8 Answer D 2 / 5 = 2 * 2 / 5 * 2 = 4 / 10 - 9 / 10 - 2 / 5 = - 9 / 10...

*October 14, 2016*

**Algebra**

- 2 x + 2 y + 3 z = 0 Multiply both sides by - 1 2 x - 2 y - 3 z = 0 - 2 x + 2 y + 3 z = 0 + 2 x + 3 y + 3 z = 5 _________________ 5 y + 6 z = 5 2 x - 2 y - 3 z = 0 + - 2 x - y + z = - 3 __________________ - 3 y - 2 z = - 3 Multiply both sides by 3 - 9 y - 6 z = - 9 - 9 y - 6 ...

*October 14, 2016*

**Algebra**

2 x + 2 z = 4 Divide both sides by 2 x + z = 2 Subtract z to both sides x + z - z = 2 - z x = 2 - z Replace x = 2 - z in equation - x - y - z = - 8 - x - y - z = - 8 - ( 2 - z ) - y - z = -8 - 2 + z - y - z = - 8 - 2 - y + z - z = - 8 - 2 - y = - 8 Add 2 to both sides - 2 - y...

*October 14, 2016*

**Plane and solid geometry**

2 x ^ 2 + 4 y ^ 2 - 12 x - 64 y - 16 = 0 Add 16 to both sides 2 x ^ 2 + 4 y ^ 2 - 12 x - 64 y - 16 + 16 = 0 + 16 2 x ^ 2 + 4 y ^ 2 - 12 x - 64 y = 16 2 x ^ 2 - 12 x + 4 y ^ 2 - 64 y = 16 2 ( x ^ 2 - 6 x ) + 4 ( y ^ 2 - 16 y ) = 16 Divide both sides by 4 2 ( x ^ 2 - 6 x ) / 4...

*October 12, 2016*

**maths**

Half distance = 50 km The first half: 50 km / 40 km/h = 1.25 h The second half: 50 km / 80 km/h = 0.625 h Total time of the travel = 1.25 h + 0.625 h = 1.875 h average speed = 100 km / 1.875 h = 53.333 km / h

*October 12, 2016*

**math**

But if your question mean: The total number of students in a school is 1650. 70% of the pupils are boys. How many girls are there in the school? Then: 70% of the pupils are boys. 100 % - 70 % = 30 % 30% of the pupils are girls. 30 % = 30 / 100 = 0.3 0.3 * 1650 = 495 The total ...

*October 12, 2016*

**math**

The total number of students in a school can't be 1650.70%.

*October 12, 2016*

**Math**

40 % = 40 / 100 = 0.4 0.4 * 33 = 13.2

*October 7, 2016*

**Math**

30 % = 30 / 100 = 0.3 0.3 * 80 = 24

*October 7, 2016*

**math**

( 4 / 7 ) x = - 16 Multiply both sides by 7 4 x = - 16 * 7 4 x = - 112 Divide both sides by 4 x = - 112 / 4 = - 28 Answer B 4 s + 13 + s = 2 s + 40 - 6 5 s + 13 = 2 s + 34 Subtract 2 s to both sides 5 s + 13 - 2 s = 2 s + 34 - 2 s 3 s + 13 = 34 Subtract 13 to both sides 3 s + ...

*October 7, 2016*

**Math**

0.67 = 67 / 100 0.3 = 3 / 10 0.67 * 0.3 = 67 / 100 * 3 / 10 = 67 * 3 / ( 100 * 10 ) = 201 / 1000 = 0.201

*October 7, 2016*

**mystery number math please help**

The digit in the hundreds place is 3 times greater than the digit in the ones place. The digit in the ones place is 6 less than the digit in the hundred thousands place. If you mark digit in the one place with x and digit in the hundreds place with h this mean: h = 3 x and x...

*October 6, 2016*

**Math**

a = larger number b = smaller number The difference of two number is seven mean: a - b = 7 a - b = 7 Add b to both sides a - b + b = 7 + b a = 7 + b a = b + 7 When the larger number is decreased by five, then doubled, it is five more than the small number mean: ( a - 5 ) * 2...

*October 4, 2016*

**Math**

Your answer is partially correct. 4 ( 9 + 6 ) = 4 * 15 = 60 But also: 36 = 12 * 3 24 = 12 * 2 36 + 24 = 12 * 3 + 12 * 2 = 12 ( 3 + 2 ) 12 * ( 3 + 2 ) = 12 * 5 = 60 Answers b and d

*October 4, 2016*

**MATH**

If the initial term of an arithmetic progression is a a1 and the common difference of successive members is d, then the nth term of the AP is given by: an = a1 + ( n - 1 ) d a4 = a1 + ( 4 - 1 ) d a4 = a1 + 3 d = - 3 a9 = a1 + ( 9 - 1 ) d a9 = a1 + 8 d = 12 Now you must solve ...

*October 3, 2016*

**maths**

a / b = 3 / 4 Multiply both sides by b a = ( 3 / 4 ) b a + b = 84 ( 3 / 4 ) b + b = 84 ( 3 / 4 ) b + ( 4 / 4 ) b = 84 ( 7 / 4 ) b = 84 Multiply both sides by 4 7 b = 84 * 4 7 b = 336 Divide both sides by 7 b = 336 / 7 = 48 b = 48 a = ( 3 / 4 ) b = 3 * 48 / 4 = 144 / 4 = 36 a...

*October 3, 2016*

**maths**

a / b = 2 / 3 Multiply both sides by b a = ( 2 / 3 ) b a + b = 30 ( 2 / 3 ) b + b = 30 ( 2 / 3 ) b + ( 3 / 3 ) b = 30 ( 5 / 3 ) b = 30 Multiply both sides by 3 5 b = 30 * 3 5 b = 90 Divide both sides by 5 b = 90 / 5 = 18 a = ( 2 / 3 ) b = 2 * 18 / 3 = 36 / 3 = 12 a / b = 12 / ...

*October 3, 2016*

**math 115**

Reiny Volume isn't (100)(290)(29) km^3 a river is 100 kilometers long 290 meters wide and 29 meters deep 1 km = 1000 m 1 m = 1 / 1000 m 290 m = 290 / 1000 = 0.29 km 29 m = 29 / 1000 = 0.029 km Volume = ( 100 * 0.29 * 0.029 ) km ^ 3 = 0.841 km ^ 3 = 8.41 * 10 ^ - 1 km ^ 3

*October 3, 2016*

**math 115**

1 m = 10 dm 1 km = 1,000 m = 10,000 dm 100 km * 290 m * 29 m = 100 * 10,000 dm * 290 * 10 dm * 29 * 10 dm = ( 1,000,000 * 2,900 * 290 ) dm ^ 3 = ( 10 ^ 6 * 2.9 * 10 ^ 3 * 2.9 * 10 ^ 2 ) dm ^ 3 = ( 10 ^ 6 * 10 ^ 3 * 10 ^ 2 ) * ( 2.9 * 2.9 ) dm ^ 3 = ( 10 ^ 11 * 2.9 ^ 2 ) dm ^ 3...

*October 3, 2016*

**Math (Trig Review)**

tan ( arctan x ) = x cot x = 1 / tan x tan ( arccot x ) = tan [ arc (1 / tan x ) ] = 1 / tan ( arctan x ) = 1 / x tan ( arccot 2 ) = tan [ arc (1 / tan 2 ) ] = 1 / tan ( arctan 2 ) = 1 / 2

*September 30, 2016*

**math**

4 ( x + 3 ) = 5 x - 2 4 * x + 4 * 3 = 5 x - 2 4 x + 12 = 5 x - 2 Subtract 4 x to both sides 4 x + 12 - 4 x = 5 x - 4 x - 2 12 = x - 2 Add 2 to both sides 12 + 2 = x - 2 + 2 14 = x x = 14

*September 29, 2016*

**Math**

S = Sheila´s money R = Rita´s money Sheila and Rita had $300 mean: S + R = 300 S + R = 300 Subtract S to both sides S + R - S = 300 - S R = 300 - S After Shiela gave $56 to Rita, Shiela had: S - 56 dollars Rita had: R + 56 = 300 - S + 56 = 356 - S Rita had 5 times ...

*September 29, 2016*

**carson high school**

5 r - 3 s = 19 Multiply both sides by - 2 5 r * ( - 2 ) - 3 s * ( - 2 ) = 19 * ( - 2 ) - 10 r + 6 s = - 38

*September 29, 2016*

**carson high school**

5 r - 3 s = 19 Multiply both sides by - 2 - 5 r * ( - 2 ) - 3 s * ( - 2 ) = 19 * ( - 2 ) - 10 r + 6 s = - 38 Now your system become: - 10 r + 6 s = - 38 + 2 r - 6 s = - 2 __________________ - 10 r + 2 r + 6 s - 6 s = - 38 + ( - 2 ) - 8 r = - 38 - 2 - 8 r = - 40 Divide both ...

*September 29, 2016*

**Algabra**

D = Dick's age T = Tom's age H = Harry's age M = Mother's age D < T D > H D = T - 2 Add 2 to both sides D + 2 = T - 2 + 2 D + 2 = T T = D + 2 M = 3 D also: M = 2 T + 13 = 2 ( D + 2 ) + 13 = 2 * D + 2 * 2 + 13 = 2 D + 4 + 13 = 2 D + 17 M = M 3 D = 2 D + 17...

*September 26, 2016*

**Algebra**

6 = 6 * 3 / 3 = 18 / 3 6 = x + 2 / 3 18 / 3 = x + 2 / 3 Subtract 2 / 3 to both sides 18 / 3 - 2 / 3 = x + 2 / 3 - 2 / 3 16 / 3 = x x = 16 / 3

*September 21, 2016*

**Math**

1 / 2 = 1 * 4 / ( 2 * 4 ) = 4 / 8 1 / 2 + 3 / 8 = 4 / 8 + 3 / 8 = 7 / 8

*September 21, 2016*

**Matrices**

In google type: 2x2 System of Equations - Solver that Shows Steps When you see list of results clik on: 2x2 System of Equations - Solver that Shows Steps - Math Lessons When page be open type your coefficients: 3 , - 9 , 30 and 2 , 5 , -2 Click on: Solve by using Cramer's ...

*September 21, 2016*

**Maths - Ratio**

A = Angelique's ages S = Serena’s ages V = Venus’ ages A / S = 5 / 3 S / V = 6 / 5 Angelique is 25 years older than Venus mean: A = V + 25 Replace this value in equation: A / S = 5 / 3 ( V + 25 ) / S = 5 / 3 Multiply both sides by S V + 25 = 5 S / 3 Multiply both...

*September 21, 2016*

**Pre algebra**

Replace s = 4 and t = 8 in your equation. 2 s t ^ 2 - s ^ 2 = 2 * 4 * 8 ^ 2 - 4 ^ 2 = 2 * 4 * 64 - 16 = 8 * 64 - 16 = 512 - 16 = 496

*September 14, 2016*

**Math HELP!**

3 / 4 = 0.75 - 5 / 6 = - 0.833 0.75 > - 0.833 3 / 4 > - 5 / 6 - 1 3/4 = - 1.75 3 / 4 = 0.75 - 1.75 < 0.75 - 1 3/4 < 3 / 4 2 3/4 = 2.75 2 4/6 = 2 2/3 = 2.666 2.75 > 2.666 2 3/4 > 2 4/6

*September 13, 2016*

**maths**

A = P ( 1 + r / n ) ^ ( n * t ) A = total amount P = principal or amount of money deposited, r = annual interest rate n = number of times compounded per year t = time in years In this case : P = 224000 R = 2 % = 2 / 100 = 0.02 n = 1 t = 16 A = P ( 1 + r / n ) ^ ( n * t ) A = P...

*September 13, 2016*

**geometry**

Area of a regular hexagon = [ 3 sqroot ( 3 ) / 2 ] * a ^ 2 Where, a is the side of the hexagon. A = [ 3 sqroot ( 3 ) / 2 ] * a ^ 2 A = [ 3 sqroot ( 3 ) / 2 ] * 4 ^ 2 A = [ 3 sqroot ( 3 ) / 2 ] * 16 A = [ 3 sqroot ( 3 ) / 2 ] * 2 * 8 A = 3 sqroot ( 3 ) * 8 A = 24 sqroot ( 3 ) ...

*September 13, 2016*

**math**

If your expression mean: ( 3.96 x 10 ^ 2 ) / ( 1.5 x 10 ^ 6 ) then: 3.96 x 10 ^ 2 / 1.5 x 10 ^ 6 = ( 3.96 / 1.5 ) * ( 10 ^ 2 / 10 ^ 6 ) = 2.64 x 10 ^ ( 2 - 6 ) = 2.64 x 10 ^ -4

*August 31, 2016*

**math**

15 2/6 = 15 + 2 / 6 = 15 * 6 / 6 + 2 / 6 = 90 / 6 + 2 / 6 = 92 / 6 Multiply both sides by 4 4 * 92 / ( 4 * 6 ) = 368 / 24 15 2/6 = 368 / 24 9 1/4 = 9 + 1 / 4 = 9 * 4 / 4 + 1 / 4 = 36 / 4 + 1 / 4 = 37 / 4 Multiply both sides by 6 6 * 37 / ( 6 * 4 ) = 222 / 24 9 1/4 = 222 / 24 ...

*August 31, 2016*

**Maths**

A = b * h / 2 = [ ( 11 / 2 ) * ( 7 / 3 ) ] / 2 = ( 77 / 6 ) / 2 = 77 / 12

*August 31, 2016*

**Math**

17 - 2 * 3 - 8 = 3 17 - 6 - 8 = 11 - 8 = 3 33 / 3 - 2 * 5 = 1 11 - 10 = 1

*August 31, 2016*

**math**

( 1 + x + x ^ 2 ) ^ 3 = [ ( 1 + x ) + x ^ 2 ] ^ 3 Now use formulas: ( a + b ) ^ 2 = a ^ 2 + 2 a b + b ^ 2 and ( a + b ) ^ 3 = a ^ 3 + 3 a ^ 2 * b + 3 a * b ^ 2 + b ^ 3 [ ( 1 + x ) + x ^ 2 ] ^ 3 = ( 1 + x ) ^ 3 + 3 ( 1 + x ) ^ 2 * x ^ 2 + 3 ( 1 + x ) * ( x ^ 2 ) ^ 2 + ( x ^ 2...

*August 31, 2016*

**Urgent Math**

OR cot ( 2x ) - csc ( 2x ) = cos ( 2x ) / sin ( 2x ) - 1 / sin ( 2x ) = [ cos ( 2x ) - 1 ) ] / sin ( 2x ) Since the: cos ( 2x ) = cos ^ 2 x - sin ^ 2 x sin ( 2 x ) = 2 sin x cos x you can write: cot ( 2x ) - csc ( 2x ) = ( cos ^ 2 x - sin ^ 2 x - 1 ) / 2 sin x cos x = [ ( - 1...

*August 28, 2016*

**Math**

210,004,050

*August 28, 2016*

**algebra**

l = length w = width P = perimeter l = 2 w P = 2 ( l + w ) = 126 2 ( 2 w + w ) = 126 2 * 3 w = 126 6 w = 126 w = 126 / 6 = 21 ft l = 2 w = 2 * 21 = 42 ft

*August 28, 2016*

**Math**

A = b * h / 2 14 = 4 * h / 2 14 = 2 h h = 14 / 2 = 7

*August 28, 2016*

**Math**

g = the greater part s = the smaller part 2 g = 3 s Divide both sides by 2 g = ( 3 / 2 ) s g + s = 75 ( 3 / 2 ) s + s = 75 ( 3 / 2 ) s + ( 2 / 2 ) s = 75 ( 5 / 2 ) s = 75 Multiply both sides by 2 5 s = 75 * 2 5 s = 150 Divide both sides by 5 s = 150 / 5 s = 30 g = ( 3 / 2 ) s ...

*August 27, 2016*