Tuesday

January 24, 2017
Total # Posts: 2,320

**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*

**CGTC**

9 % = 9 / 100 = 0.09 7 % = 7 / 100 =0.07 x = the amount of money $100 less then three times the amount = 3 x - 100 x * 0.09 + ( 3 x - 100 ) * 0.07 = 83 0.09 x + 3 x * 0.07 - 100 * 0.07 = 83 0.09 x + 0.21 x - 7 = 83 0.3 x - 7 = 83 0.3 x = 83 + 7 0.3 x = 90 x = 90 / 0.3 x = 300 ...

*August 27, 2016*

**Math**

"Prime Factorization" is finding which prime numbers multiply together to make the original number. In this case: 6 = 2 * 3 = 2 ^ 1 * 3 ^ 1 9 = 3 ^ 2 15 = 3 * 5 = 3 ^ 1 * 5 ^ 1 The highest power of the three prime numbers 2, 3, and 5 is: 2 ^ 1 = 2 3 ^ 2 = 9 5 ^ 1 = 5...

*August 27, 2016*

**Math**

1 * 300,000 / 10 = 300,000 / 10 = 30,000

*August 25, 2016*

**Math**

V = A * h 7,168 = 521 h Divide both sides by 512 7,168 / 512 = h 14 = h h = 14 cm

*August 24, 2016*

**Math**

|- 8| = 8 - 6 < |- 8| -6 < 8 Answer B

*August 24, 2016*

**pre calculus honors**

x + y + z = 15 7 x + y + z = 75 3 x + y - z = 29 Multiply first equation by − 7 ( x + y + z = 15 ) * ( - 7 ) -7 x - 7 y - 7 z = - 105 add this to the second equation -7 x - 7 y - 7 z = - 105 + 7 x + y + z = 75 ____________________ The result is: - 6 y - 6 z = - 30 Divide...

*August 24, 2016*

**math**

Yes

*August 23, 2016*

**Math**

( x + 1 ) * 500500 = 500500 ( x + 1 )

*August 20, 2016*

**Math**

If you in google type: Sum of numbers 1 to 100 By the way: 1 + 2 + 3 + 4 + . . . . + n = ( 1 + n )*( n / 2 ) 1 + 2 + 3 +…100 n = 100 1 + 2 + 3 +…100 =( 1 + 100 ) * ( 100 / 2 ) = 101 * 50 = 5050 ( x + 1 ) + 2 ( x + 1) + …+ 1000 ( x + 1 ) = ( x + 1 ) ( 1 + 2 +......

*August 20, 2016*

**Math**

This is calculus problem. In an open box you have square base with area a ^ 2 and 4 rectangle with area a * h where a is length of base and h is height of box Area of an open box: A = a ^ 2 + 4 a * h A = a ^ 2 + 4 a * h = 24 Subtract a ^ 2 to both sides a ^ 2 + 4 a * h - a ^ 2...

*August 19, 2016*

**Math**

22 - 10 = 12 34 - 22 = 12 46 - 34 = 12 58 - 46 = 13 70 - 58 = 12 Missing number = 70

*August 16, 2016*

**math**

25 = 5 * 5 35 = 5 * 7 1.25 = 5 / 4 25 / 35 = 1.25 / x become: 5 * 5 / ( 5 * 7 ) = 5 / 4x 5 / 7 = 5 / 4x Divide both sides by 5 1 / 7 = 1 / 4x Multiply both sides by x x / 7 = 1 / 4 Multiply both sides by 7 x = 7 / 4 = 1.75

*August 16, 2016*

**Maths**

16 baqgs * 1.5 kg = 24 kg $672 / 24 kg = $28 / kg 18 bags * 2 kg = 36 kg 36 kg * $28 / kg = $ 1,008 OR 16 * 1.5 / ( 18 * 2 ) = 672 / x 24 / 36 = 672 / x 2 * 12 / ( 3 * 12 ) = 672 / x 2 / 3 = 672 / x 2 * x = 3 * 672 2 x = 2,016 x = 2,016 / 2 x = $ 1,008

*August 15, 2016*

**math**

625 = 25 * 25 ã625 = 25 sqroot ( ã625 ) = sqroot ( 25 ) = 5

*August 15, 2016*

**Algebra**

-5 > -8 Draw a number line: 0, - 1, - 2, - 3, - 4 , - 5, - 6 , - 7, - 8, - 9...

*August 12, 2016*

**math**

In your case x and y coordinates are: x1 = 0, x2 = 2, x3 = 4, x4 = 6 y1 = - 3, y2 = - 2, y3 = -1, y4 = 0 slope = change in y / change in x This mean, divide the change in height by the change in horizontal distance. slope = ( y2 - y1 ) / ( x2 - x1 ) = [ - 2 - ( - 3 ) ] / ( 2...

*August 12, 2016*

**maths**

Sum of a certain number of terms of an arithmetic sequence: Sn = n ( a1 + an ) / 2 In this case: S9 = 9 ( a1 + a9 ) / 2 = 279 S20 = 20 ( a1 + a20 ) / 2 = 1280 9 ( a1 + a9 ) / 2 = 279 Multiply both sides by 2 9 ( a1 + a9 ) = 279 * 2 9 a1 + 9 a9 = 558 On the other side: an = a1...

*August 11, 2016*

**math**

Replace 2 instead p in your equation. ( 34 + 18 p ) - ( 5 + p ) = ( 34 + 18 * 2 ) - ( 5 + 2 ) = 34 + 36 - 7 = 70 - 7 = 63

*August 11, 2016*

**math**

A perfect square is a number that can be expressed as the product of two equal integers. 169 = 13 * 13 A perfect cube is a number that can be expressed as the product of three equal integers. 169 = 5.5287748 * 5.5287748 * 5.5287748 5.5287748 isn't whole number so 169 is a ...

*August 11, 2016*

**math**

100.1 % = 100.1 / 100 ( 100.1 / 100 ) * ( 10 / 10 ) = 1001 / 1000 100.1 % = 1001 / 1000

*August 11, 2016*

**Algebra**

60 * 4 / 5 = 240 / 5 = 48 48 students are members of Math Club. Among the members, 3 / 5 are girls: 48 * 3 / 5 = 144 / 5 = 28.8 girls 48 - 28.8 = 19.2 boys Your question does not make sense.

*August 11, 2016*

**math**

S = Present Sam's age B = Present brother's age Sam is one-third as old as his brother mean: S = B / 3 After six year Sam will be S + 6 years od. Brother will be B + 6 years old. In six years Sam will be one-half as old mean: ( S + 6 ) / ( B + 6 ) = 1 / 2 Now you must ...

*August 11, 2016*

**Maths**

a + b = 14 a * b = 40 a + b = 14 Subtract a to both sides a + b - a = 14 - a b = 14 - a a * b = 40 a * ( 14 - a ) = 40 14 a - a ^ 2 = 40 - a ^ 2 + 14 a = 40 Subtract 40 to both sides - a ^ 2 + 14 a - 40 = 40 - 40 - a ^ 2 + 14 a - 40 = 0 Multiply both sides by - 1 a ^ 2 - 14 a...

*August 7, 2016*

**math**

a1 + a2 + a3 + a4 + a5 = 44 The sum of a certain number of terms of a geometric sequence: Sn = a1 * ( 1 - r ^ n ) / ( 1 - r ) In this case you have 5 terms: a1 + a2 + a3 + a4 + a5 = 44 S5 = a1 * ( 1 - r ^ 5 ) / ( 1 - r ) = 44 a1 * ( 1 - r ^ 5 ) / ( 1 - r ) = 44 The sum of the ...

*August 7, 2016*

**Precalculus**

sin u = 4 / 5 cos u = sqroot ( 1 - sin ^ 2 u ) cos u = sqroot [ 1 - ( 4 / 5 ) ^ 2 ] cos u = sqroot ( 1 - 16 / 25 ) cos u = sqroot ( 25 / 25 - 16 / 25 ) cos u = sqroot ( 9 / 25 ) cos u = ± 3 / 5 In Quadrant II cos is negative so: cos u = - 3 / 5 sin v = - 12 /13 cos v = ...

*August 3, 2016*

**Math**

L = 2 W P = 2 L + 2 W = 2 ( L + W ) P = 54 2 ( L + W ) = 54 Divide both sides by 2 L * W = 54 / 2 L + W = 27 Replace L = 2 W in this equation. 2 W + W = 27 3 W = 27 Divide both sides by 3 W = 27 / 3 W = 9 m L = 2 W = 2 * 9 = 18 m Proof: P = 2 ( L + W ) = 2 ( 18 + 9 ) = 2 * 27...

*August 3, 2016*

**pre cal**

sin u = 1 / 3 cos u = sqroot [ 1 - sin u ) ^ 2 ] sqroot [ 1 - ( 1 / 3 ) ^ 2 ] = sqroot ( 1 - 1 / 9 ) = sqroot ( 9 / 9 - 1 / 9 ) = sqroot ( 8 / 9 ) = sqroot ( 4 * 2 / 9 ) = sqroot ( 4 / 9 ) * sqroot ( 2 ) = + OR - ( 2 / 3 ) * sqroot ( 2 ) cos u = + OR - 2 sqrt ( 2 ) / 3 sin v...

*August 3, 2016*

**pre algebra**

L = larger numbr S = smaller number The difference between two numbers is 44 mean: L - S = 44 Five times the smaller is equal to 8 more than the larger mean: 5 S = L + 8 Now youust solve sytem of two equation with two unknow. L - S = 44 5 S = L + 8 L - S = 44 Add S to both ...

*July 30, 2016*

**Math**

4*15-11+8-2=20 ______________________ 4*1(5-1)-1(+8/-2)= 4 * 1 * 4 - 1 * ( - 4 ) = 16 + 4 = 20

*July 30, 2016*

**Maths**

1st term: n = 1 Sn = 3 n - 2 S1 = 3 * 1 - 2 = 3 - 2 = 1 3rd term: n = 3 Sn = 3 n - 2 S3 = 3 * 3 - 2 = 9 - 2 = 7 5th term: n = 5 Sn = 3 n - 2 S5 = 3 * 5 - 2 = 15 - 2 = 13

*July 30, 2016*

**pre cal**

A cubic function is a function of the form: f ( x ) = a ^ 3 + b x ^ 2 + c x + d You must find 4 coefficients: a , b , c , and d You now zero pionts: x = - 5 , y = 0 x = 2 , y = 0 and x = 4 , y = 0 You also know : f ( - 10 ) = - 4 Now put this values in equation: f ( x ) = a x...

*July 27, 2016*

**Math**

12 * 20 = 240

*July 23, 2016*

**Math**

n = 2 didit number a = tens b = ones So: n = 10 a + b The number exceeds the sum of digits by18 mean: n = a + b + 18 Now equalize exspressions for n. n = n 10 a + b = a + b + 18 Subtract b to both sides 10 a + b - b = a + b + 18 - b 10 a = a + 18 Subtract a to both sides 10 a...

*July 23, 2016*

**math**

3 / 7 = 15 / x Multiply both sides by x 3 x / 7 = 15 Multiply both sides by 7 3 x = 15 * 7 3 x = 105 Divide both sides by 3 x = 105 / 3 x = 35 3 / 7 = 15 / 35

*July 22, 2016*

**math**

1 h 45 min = 60 min + 45 min = 105 min 24 / 105 = 64 / x Muultiply both sides bx x 24 x / 105 = 64 Multiply both sides by 105 24 x = 64 * 105 24 x = 6720 Divide both sides by 24 x = 6720 / 24 = 280 min x = 240 min + 40 min = 4 * 60 min + 40 min = 4 h 40 min OR 64 / 24 = 8 * 8...

*July 22, 2016*

**Math**

a) 13 , 17 , 25 , 27 , 28 , x , 32 , 36 , 37 , 40 , y , 47 The median is the middle number. But there is no "middle" number, because there are an even number of numbers. In this case, the median is the mean (the usual average) of the middle two values: The median...

*July 22, 2016*

**math**

x = present age In five years time thabo will be three times as old as he was nine years ago, mean: 5 + x = 3 ( x - 9 ) 5 + x = 3 x - 27 Subtract x to both sides 5 + x - x = 3 x - 27 - x 5 = 2 x - 27 Add 27 to both sides 5 + 27 = 2 x - 27 + 27 32 = 2 x Divide both sides by 2 ...

*July 22, 2016*

**Math**

x ^ - 1/4 = 4 ^ -1/2 mean: 1 / fourth root of x = 1 / square root of 4 1 / fourth root of x = 1 / 2 Taking reciprocial of both sides: fourth root of x = 2 Rise both sides to the power of four x = 2 ^ 4 x = 16 q^ 1/2 = x mean : square root of q = x Rise both sides to the power ...

*July 19, 2016*

**Math**

c and d are positive consecutive odd integers mean : c = d + 2 becouse : if d are odd integers, next integer are d + 2 So: c + d = 240 d + d + 2 = 240 2 d + 2 = 240 Subtract 2 to both sides 2 d + 2 - 2 = 240 - 2 2 d = 238 Divide both sides by2 d = 238 / 2 = 119 c = d + 2 c = ...

*July 19, 2016*

**Math**

| a - 2 | = 9 a - 2 = + OR - 9 1 solution: a - 2 = 9 Add 2 to both sides a - 2 + 2 = 9 + 2 a = 11 2 solution: a - 2 = - 9 Add 2 to both sides a - 2 + 2 = - 9 + 2 a = - 7 | w - 1 | = 6 w - 1 = + OR - 6 1 solution: w - 1 = 6 Add 1 to both sides w - 1 = 6 + 1 w = 7 2 solution: w...

*July 19, 2016*

**Math**

first number: a second number: a + 1 third number: a + 2 fourth number: a + 3 fifth number: a + 4 a + a + 1 + a + 2 + a + 3 + a + 4 = 80 5 a + 10 = 80 Subtract 10 to both sides 5 a + 10 - 10 = 80 - 10 5 a = 70 Divide both sides by 5 a = 70 / 5 = 14 The numbers : 14, 15, 16, 17...

*July 19, 2016*

**math**

g = the greater angle s = the smaller angle = g / 2 The sum of the angles in a triangle is 180 ° 60 ° + g + s = 180 ° 60 ° + g / 2 + g = 180 ° 60 ° + g / 2 + 2 g / 2 = 180 ° 60 ° + 3 g / 2 = 180 ° Subtract 60 ° to both sides 3 g / 2 = ...

*July 19, 2016*

**math**

cos ^ 2 A = 1 - sin ^ 2 A cos ^ 6 A + sin ^ 6 A = ( 1 - sin ^ 2 A ) ^ 3 + ( sin ^ 2 A ) ^ 3 = _________________________________Remark : ( a - b ) ^ 3 = a ^ 3 - 3 a ^ 2 b + 3 a b ^ 2 - b ^ 3 In case ( 1 - sin ^ 2 A ) ^ 3 a = 1, b = sin ^ 2 A so : ...

*July 18, 2016*

**math**

S = number of students g = number of girls b = number of boys b = g + 17 S = g + b S = g + g + 17 S = 2 g + 17 g = 4 / 9 S so : S = 2 * ( 4 / 9 ) S + 17 S = ( 8 / 9 ) S + 17 Subtract ( 8 / 9 ) S to both sides S - ( 8 / 9 ) S = ( 8 / 9 ) S + 17 - ( 8 / 9 ) S ( 9 / 9 ) S - ( 8...

*July 7, 2016*

**Pre-Cal**

Use Trigonometric Identities : sin ( x / 2 ) = + OR - sqroot [ ( 1 - cos x ) / 2 ] cos ( x / 2 ) = + OR - sqroot [ ( 1 + cos x ) / 2 ] 0° < x < 90° meen x lies in Quadrant I In Quadrant I sin x and cos x are positive so : sin ( x / 2 ) = sqroot [ ( 1 - cos x ) / ...

*July 7, 2016*

**math**

30 = 8 * sqroot ( h - 40 ) Divide both sides by 8 30 / 8 = sqroot ( h - 40 ) 2 * 15 / ( 2 * 4 ) = sqroot ( h - 40 ) 15 / 4 = sqroot ( h - 40 ) Raise both sides to the power of two : ( 15 / 4 ) ^ 2 = h - 40 225 / 16 = h - 40 Add 40 to both sides 225 / 16 + 40 = h - 40 + 40 225...

*July 6, 2016*

**math**

3 x / 4 - 16 = 44 Add 16 to both sides 3 x / 4 - 16 + 16 = 44 + 16 3 x / 4 = 60 Multiply both sides by 4 3 x = 240 Divide both sides by 3 x = 240 / 3 x = 80 Proof : 3 * 80 / 4 - 16 = 240 / 4 - 16 = 60 - 16 = 44

*July 2, 2016*

**Mathematics**

P ( x ) = x ^ 3 + 2 x ^ 2 - 11 x - 12 This is a polynomial of degree 3. To find zeros for polynomials of degree 3 or higher we use Rational root test. The Rational Root Theorem tells you that if the polynomial has a rational zero then it must be a fraction p / q, where p is a ...

*July 2, 2016*

**math**

W / L = 60 / 80 = 20 * 3 / 20 * 4 = 3 / 4

*July 2, 2016*

**Math**

A = Ama's ages K = Karla's ages D = Daniel's ages Ama is 3 years older than Karla this mean : A = K + 3 Daniel is 2 years older than Ama this mean : D = A + 2 The sum of their ages is 32 this mean : A + K + D = 32 Now you have 3 equatios : A = K + 3 D = A + 2 A + K...

*June 25, 2016*

**Math**

x = 10% = 10 / 100 = 0.1 10% acid solution of 40 mL = 0.1 * 40 mL = 4 mL of acid Volume of new acid solution = 40 mL + x where x = volume of added wather 4 mL represent 4 % 4 % = 4 / 100 = 0.04 Now 4 mL of acid / new volume = 4 % =0.04 4 mL / ( 40 mL + x ) = 0.04 In ...

*June 24, 2016*

**Math**

4 3 / 5 = 4 + 3 / 5 = 4 * 5 / 5 + 3 / 5 = 20 / 5 + 3 / 5 = 23 / 5 ( 2 / 3 ) / 4 3 / 5 = ( 2 / 3 ) / ( 23 / 5 ) = 2 * 5 / ( 3 * 23 ) = 10 / 69 pounds

*June 12, 2016*

**math**

3 ( x - 2 ) ^ 2 - 12 = 0 Divide both sides by 3 3 ( x - 2 ) ^ 2 / 3 - 12 / 3 = 0 / 3 ( x - 2 ) ^ 2 - 4 = 0 Add 4 to both sides ( x - 2 ) ^ 2 - 4 + 4 = 0 + 4 ( x - 2 ) ^ 2 = 4 Take square root of both sides x - 2 = + OR - sqroot ( 4 ) x - 2 = + OR - 2 1 solution : x - 2 = - 2 ...

*June 12, 2016*

**algebra**

Yes. ( x + c ) ^ 2 = x ^ 2 + 2 * x * c + c ^ 2 In this case : 2 x c = 14 x Divide both sides bny 2 x 2 x c / 2 x = 14 x / 2 x c = 7 So : ( x + c ) ^ 2 = x ^ 2 + 2 * x * c + c ^ 2 ( x + 7 ) ^ 2 = x ^ 2 + 2 x * 7 + 7 ^ 2 = x ^ 2 + 14 x + 49

*June 1, 2016*

**algebra 1**

x ^ 8 * 2 y ^ 10 * 5 x ^ 5 = 2 * 5 * x ^ 8 * x ^ 5 * y ^ 10 = 10 x ^ ( 8 + 5 ) * y ^ 10 = 10 x ^ 13 y ^ 10

*June 1, 2016*

**Algebra**

f ( x ) = - x ^ 2 + 5 x + 4 f ( 3 ) = - 3 ^ 2 + 5 * 3 + 4 = - 9 + 15 + 4 = 10 f ( 5 ) = - 5 ^ 2 + 5 * 5 + 4 = - 25 + 25 + 4 = 4 The average rate of change : [ f ( 5 ) - f ( 3 ) ] / ( 5 - 3 ) = ( 10 - 4 ) / ( 5 - 3 ) = 6 / 2 = 3 Answer A

*May 24, 2016*

**Maths (Need Help)**

If y^2-1/4y=0 mean : y ^ 2 - ( 1 / 4 ) y = 0 then : Write y ^ 2 like : 4 y ^ 2 / 4 Now : 4 y ^ 2 / 4 - ( 1 / 4 ) y = 0 ( 1 / 4 ) 4 y - ( 1 / 4 ) y = 0 ( 1 / 4 ) ( 4 y ^ 2 - y ) = 0 ( 1 / 4 ) y ( 4 y - 1 ) = 0 Now you must solwe two equations : ( 1 / 4 ) y = 0 and 4 y - 1 = 0...

*May 24, 2016*

**math**

Go on : calc101.c o m When page be open click option : derivative then in rectangle Take the derivative of type : sin[cos[x^2]] and click option : DO IT You will see solution step by step.

*May 24, 2016*

**Math**

d = Diameter P = Perimeter P = d * pi = 14 * pi 4 P = 4 * 14 * pi = 56 pi = 56 * 3.14159 = 175.92904 in approx. 176 in

*May 24, 2016*