Thursday

October 20, 2016
Total # Posts: 2,236

**wave on**

Sound wave

*April 10, 2012*

**algebra**

4 y ^ 5 + 3 y -( -2 y ^ 5 - 8 y + 9 ) = 4 y ^ 5 + 3 y - ( -2 y ^ 5 ) - ( - 8 y ) - 9 = 4 y ^ 5 + 3 y + 2 y ^ 5 + 8 y - 9 = 6 y ^ 5 + 11 y - 9

*April 10, 2012*

**Geometry**

In an equilateral triangle : h = a * sqrt ( 3 ) / 2 26 = a * sqrt ( 3 ) / 2 Multiply both sides by 2 26 * 2 = a * sqrt ( 3 ) 52 = a * sqrt ( 3 ) divide both sides by sqrt ( 3 ) 52 / sqrt ( 3 ) = a 52 / 1.73205 = a 30.022228 in = a a = 30.022228 in 1 in = 2.54 cm a = 30.022228...

*April 10, 2012*

**Geometry**

Pitagorin teorem : diagonal = sqrt ( a ^ 2 + a ^ 2 ) diagonal = sqrt ( 2 * a ^ 2 ) diagonal = a * sqrt ( 2 ) 13 = a * sqrt ( 2 ) Divide both sides by aqrt ( 2 ) 13 / sqrt ( 2 ) = a 13 / 1.41421 = a 9.19241131 = a a = 9.19241131 m 1 m = 100 cm a = 9.19241131 m = 919.241131 cm a...

*April 10, 2012*

**Geometry**

diagonal = sqrt ( 95 ^ 2 + 95 ^ 2 ) diagonal = sqrt ( 2 * 95 ^ 2 ) diagonal = sqrt ( 2 * 9025 )

*April 10, 2012*

**Geometry**

Pitagorin teorem: diagonal = sqrt ( 95 ^ 2 + 95 ^ 2 ) diagonal = sqrt ( 2 * 9025 ) ---------------------- Remark : 9025 = 5 * 5 * 19 * 19 9025 = 5 ^ 2 * 19 ^ 2 ---------------------- diagonal = sqrt ( 2 * 9025 ) diagonal = sqrt ( 2 * 5 ^ 2 * 19 ^ 2 ) diagonal = 5 * 19 * sqrt...

*April 10, 2012*

**math**

BMI = 703 * w / h ^ 2 BMI = 30 h = 65 in 30 = 703 * w / 65 ^ 2 30 = 703 * w / 4225 Multiply both sides by 4225 30 * 4225 = 703 * w 126750 = 703 * w Divide both sides by 703 126750 / 703 = w 180.29872 = w w = 180.29872 lb

*April 10, 2012*

**Area Geometry**

Area of a regular polygon: A = ( 1 / 2 ) * n * r ^ 2 * sin ( 360 ° / n ) The area of a decagon: ( n = 10 ) ( r = 4 mm ) ( sin 36 ° = sqrt [ 10 - 2 sqrt ( 5 ) ] / 4 A = ( 1 / 2 ) * 10 * 4 ^ 2 * sin ( 360 ° / 10 ) A = 10 / 2 * 16 * sin ( 36 ° ) A = 5 * 16 * sin...

*April 10, 2012*

**algebra 1**

If 3/5g+4=6 1/3 mean 3 / ( 5 g ) + 4 = 6 1 / 3 then: 3 / ( 5 g ) + 4 = 6 1 / 3 3 / ( 5 g ) = 6 1 / 3 - 4 3 / ( 5 g ) = 2 1 / 3 3 / ( 5 g ) = 6 / 3 + 1 / 3 3 / ( 5 g ) = 7 / 3 Multiply both sides by 3 3 * 3 / ( 5 g ) = 7 9 / ( 5 g ) = 7 Mulitiply both sides by g 9 / 5 = 7 g ...

*April 9, 2012*

**trig**

3 cos ^ 2 theta - 5 cos theta - 1 - 3 sin ^ 2 theta = 0 3 cos ^ 2 theta - 5 cos theta - 1 - 3 ( 1 - cos ^ 2 theta ) = 0 3 cos ^ 2 theta - 5 cos theta - 1 - 3 + 3 cos ^ 2 theta = 0 6 cos ^ 2 theta - 5 cos theta - 4 = 0 Substitute : u = cos theta 6 u ^ 2 - 5 u - 4 = 0 The exact ...

*April 9, 2012*

**geometry**

Volume of a cone: V = ( 1 / 3 ) * r ^ 2 * pi * h r ^ 2 * pi = B The area of the circle base V = ( 1 / 3 ) * B * h V = 138 m ^ 3 B = 46 m ^ 2 138 = ( 1 / 3 ) * 46 * h Multiply both sides by 3 3 * 138 = 1 * 46 * h 414 = 46 h Divide both sides by 46 414 / 46 = h h = 414 / 46...

*April 9, 2012*

**Math**

19 / 6 + 4 y = 8 y - 1 / 6 19 / 6 + 1 / 6 = 8y - 4 y 20 / 6 = 4 y Multiply both sides by 6 20 = 6 * 4 y 20 = 24 y 20 = 24 y Divide both sides by 24 20 / 24 = y 4 * 5 / ( 4 * 6 ) = y 5 / 6 = y y = 5 / 6

*April 7, 2012*

**Math**

In google type: quadratic equation online When you see list of results click on: Free Online Quadratic Equation Solver:Solve by Quadratic Formula When page be open in rectangle type: x ^ 2 - 6 x + 13 = 0 and click option: solve it! You wil see solution step-by-step

*April 7, 2012*

**Algebra**

(k^2+9)/((k+9)*(k+9))= (k^2+9)/(k+9)^

*April 7, 2012*

**Algebra**

k ^ 2 + 6 k + 9 = ( x + 3 ) * ( x + 3 ) k ^ 2 + 12 k + 27 = ( x + 9 ) * ( x + 3 ) ((k^2+6k+9)/(k+9)*(k+3)))*(k^2+9)/((k^2+12k+27))= ((k+3)*(k+3))/((x+9)*(k+3)) * ((k^2+9)/(((x+9)*(k+3))= ((k+3))/((x+9)) * ((k^2+9)/(((x+9)*(k+3))= (k^2+9)/((x+9)*(k+9))= (k^2+9)/(x+9)^2

*April 7, 2012*

**Math 141**

The answers a) and b) are correct. c ) ( x - 1 ) ^ ( 7 / 2 ) - ( x - 1 ) ^ ( 3 / 2 ) = ( x - 1 ) ^ ( 3 / 2 ) * [ ( x - 1 ) ^ ( 4 / 2 ) - 1 ] = ( x - 1 ) ^ ( 3 / 2 ) * [ ( x - 1 ) ^ 2 - 1 ] = ( x - 1 ) ^ ( 3 / 2 ) * [ x ^ 2 - 2x + 1 - 1 ] = ( x - 1 ) ^ ( 3 / 2 ) * ( x ^ 2 - 2x...

*April 7, 2012*

**Trig**

Supplement angle of 3 pi / 5 is: 2 pi - 3 pi / 5 = ( 10 pi - 3 pi ) /5 = 7 pi / 5 You expect somebody to do ALL your homework?

*April 7, 2012*

**Trig**

( a - b ) ( a + b ) = a ^ 2 - b ^ 2 ( 1 - sin è )( 1 + sin è ) = 1 ^ 2 - sin ^ 2 è = 1 - sin ^ 2 è = cos ^ 2 è

*April 7, 2012*

**Trig**

19 pi / 7 = ( 14 + 5 ) * pi / 7 = ( 14 / 7 ) pi + ( 5 / 7 ) pi = 2 pi + ( 5 / 7 ) pi 2 pi + theta = theta I quadrant 0 ÷ pi / 2 II quadrant pi / 2 ÷ pi III quadrant pi ÷ ( 3 / 2 ) pi IV quadrant ( 3 / 2 ) pi ÷ 2 pi theta = ( 5 / 7 ) pi theta = 0....

*April 7, 2012*

**math**

( 3 y / x ^ 4 )^ - 3 = 1 / [ ( 3 y / x ^ 4 )^ 3 ] = -------------------- Remark: 3 ^ 3 = 27 ( x ^ 4 ) ^ 3 = x ^ ( 4 * 3 ) = x ^ 12 ----------------------- 1 / ( 27 y ^ 3 / x ^ 12 ] = x ^ 12 / 27 y ^ 3

*April 7, 2012*

**Algebra 2**

x y = - 7 Divide both sides by x y = - 7 / x That equation has no solutions In google type: functions graphs online When you see list of results click on: rechneronline.de/function-graphs/ When page be open in blue rectangle type: - 7 / x Set: Range x-axis from - 25 to 25 ...

*April 6, 2012*

**math**

Pythagorean Theorem : c ^ 2 = a ^ 2 + b ^ 2 c = sqrt ( a ^ 2 + b ^ 2 ) c = sqrt ( 13 ^ 2 + 35 ^ 2 ) c = sqrt ( 169 + 1225 ) c = sqrt ( 1394 ) c = 37.336 km

*April 5, 2012*

**alg2/trig**

Quadratic equation has two real equals roots, if Discrininant Ä = 0 Ä = greek letter Delta

*April 5, 2012*

**alg2/trig**

4 x ^ 2 + 9 = kx 4 x ^ 2 - k x + 9 = 0 Quadratic equation has two real roots, if Discrininant Ä = 0 Ä = b ^ 2 - 4 * a * c In this case : a = 4 b = - k c = 9 Ä = b ^ 2 - 4 * a * c Ä = ( - k ) ^ 2 - 4 * ( 4 ) * 9 Ä = k ^ 2 - 144 = 0 k ^ 2 - 144 = 0 k ^ 2...

*April 5, 2012*

**Trig.**

è is greek letter theta

*April 5, 2012*

**Trig.**

Go on: wolframalpha dot com When page be open in rectangle type: solve 2tan^2è-2tanè=3 and click option = After few seconds when you see result click option: Show steps Solutions are : è = -58.71608 ° è = - 59 ° to the nearest degree and &...

*April 5, 2012*

**Alebra**

Divided by zero is undefined When: x - 2 = 0 x = 2 your expression is undefined.

*April 5, 2012*

**algebra**

t = 14 min M = −0.001 * t ^ 3 + 0.1 * t ^ 2 M = −0.001 * 14 ^ 3 + 0.1 * 14 ^ 2 M = −0.001 * 2744 + 0.1 * 196 M = - 2.744 + 19.6 M = 16.856 words

*April 5, 2012*

**Math-alg-calc**

x ^ ( - 1 / 7 ) = ( 1 / 2 ) mean 1 / seventh root of ( x ) = 1 / 2 reciprocal value: seventh root of ( x ) = 2 Raise both sides to the power of 7 [ seventh root of ( x ) ] ^ 7 = 2 ^ 7 x = 2 ^ 7 = 128

*April 5, 2012*

**Math**

a 1 = first number a 2 = a 1 + 1 = second number a 3 = a 1 + 2 = third number a 4 = a 1 + 3 = fourth number a 5 = a 1 + 4 = fifth number a 6 = a 1 + 5 = sixth number a 7 = a 1 + 6 = seventh number a 8 = a 1 + 7 = eighth numer a 9 = a 1 + 8 = ninth number a 10 = a 1 + 9 = tenth...

*April 4, 2012*

**Intermediate Algebra**

9 x ^ 2 + 5 x - 4 + ( - 8 x ^ 2 + 9 x - 9 ) = 9 x ^ 2 + 5 x - 4 - 8 x ^ 2 + 9 x - 9 = 9 x ^ 2 - 8 x ^ 2 + 5 x + 9 x - 4 - 9 = x ^ 2 + 14 x - 13

*April 3, 2012*

**MathLog#4**

1 / a - 1 / b = c 1 / a = c - 1 / b 1 / a = c b / b - 1 / b 1 / a = ( c b - 1 ) / b Reciprocal : a = b / ( c b - 1 )

*April 2, 2012*

**MATH HELP!**

n * ln ( a ) = ln ( a ^ n ) 2 ln ( x ) = ln ( x ^ 2 ) 3 ln ( y ) = ln ( y ^ 3 ) ( 1 / 2 ) ln ( z ) = ln [ z ^ ( 1 / 2 ) ] = ln [ sqrt ( z) ] ln ( a ) + ln ( b ) = ln ( a * b ) ln ( a ) - ln ( b ) = ln ( a / b ) In this case: 2 ln ( x ) - 3 ln ( y ) + ( 1 / 2 ) ln ( z ) = 2 ln...

*April 1, 2012*

**Trigonometry**

cos ^ 2 ( x ) = 1 - sin ^ 2 ( x ) sin ^ 2 ( x ) - cos ^ 2 ( x ) = 0 sin ^ 2 ( x ) - [ 1 - sin ^ 2 ( x ) ] = 0 sin ^ 2 ( x ) - 1 + sin ^ 2 ( x ) = 0 2 sin ^ 2 ( x ) - 1 = 0 2 sin ^ 2 ( x ) = 1 Divide both sides by 2 sin ^ 2 ( x ) = 1 / 2 sin ( x ) = ± 1 / sqrt ( 2 ) ...

*April 1, 2012*

**Intermediate Algebra**

A. x = 5 f ( 5 ) = 2 * 5 + 3.50 = 10 + 3.50 = 13.50 $ B. x = 3 / 4 f ( 3 / 4 ) = 2 * 3 / 4 + 3.50 = 6 / 4 + 3.50 = 6 / 4 + 7 / 2 = 6 / 4 + 14 / 4 = 20 / 4 = 5 $ C. f ( x ) = 50 50 = 2 x + 3.5 50 - 3. 5 = 2 x 46 . 5 = 2 x Divide both sides by 2 46.5 / 2 = x 23.25 = x x = 23.25 ...

*April 1, 2012*

**Math situations**

In google type: quadratic equation online When you see list of results click on: Free Online Quadratic Equation Solver:Solve by Quadratic Formula When page be open in rectangle type: 2 x ^ 2 - 3 x = - 6 and click option: solve it! You wil see solution step-by-step

*March 31, 2012*

**Math**

When the leading coefficient a is positive, the parabola opens up ( concave up ) For function: x ^ 2 - 2 x - 8 the leading coefficient is a = 1 function is concave up When the parabola ia concawe up all walues between roots are negative. No negative number can have a real ...

*March 31, 2012*

**algebra**

V = r ^ 2 * pi * h V = 8 ^ 2 * pi * 12 V = 64 * pi * 12 V = 2412.743 ft ^ 3

*March 31, 2012*

**maths**

252 = 2 * 2 * 3 * 3 * 7

*March 31, 2012*

**Algebra**

C = Circumference A = Area r = Radius C = 2 r pi Divide both sides with 2 pi C / 2 pi = r r = C / 2 pi A = r ^ 2 pi A = ( C / 2 pi ) ^ 2 * pi A = ( C ^ 2 / 4 pi ^ 2 ) * pi A = C ^ 2 / 4 pi A = 25 ^ 2 / 4 pi A = 625 / ( 4 * 3. 14 ) A = 625 / 12.56 A = 49.761 m ^ 2 A = approx. ...

*March 30, 2012*

**algebra**

a + 6 b = 14 - a - 2 b = - 2 --------------- 6 b - 2 b = 14 - 2 4 b = 12 Divide both sides by 4 b = 12 / 4 b = 3 a + 6 b = 14 a + 6 * 3 = 14 a + 18 = 14 a = 14 - 18 a = - 4

*March 30, 2012*

**math**

A = Area W = Width L = Length P = Perimeter A = W * L 54 = W * 9 Divide both sides by 9 54 / 9 = W 6 = W W = 6 ft P = 2 ( W + L ) P = 2 ( 9 + 6 ) P = 2 * 15 P = 30 ft

*March 30, 2012*

**Math situation**

( a - 4 ) ^ 2 = a ^ 2 - 2 * a * 4 + 4 ^ 2 = a ^ 2 - 8 a + 16 2 a ^ 2 -1 6 a + 32 = 2 * [ ( a - 4 ) ]^ 2 ( 64 a ^ 2 ) / ( 2 a ^ 2 - 16 a + 32 ) * ( 2 a - 8 ) / 8 a = ( 64 a ^ 2 / 8 a ) * ( 2a - 8 ) / 2 * [ ( a - 4 ) ] ^ 2 = 8 a * ( 2 a - 8 ) / [ 2 * [ ( a - 4 ) ]^ 2 = [ 8 a * 2...

*March 30, 2012*

**algebra**

r ^ 3 + 216 / r + 6 = r ^ 3 * r / r + 216 / r + 6 r / r = ( r ^ 4 + 216 + 6 r )/ r= ( r ^ 4 + 6 r + 216 ) / r

*March 30, 2012*

**math problem**

All parts of the uneqiations must be large of 0 Less part is ( x - 12 ) Solution x > 12

*March 30, 2012*

**Calculus**

Go on: wolframalpha dot com When page be open in rectangle type: partial fractions (x - x^3) / (x^4 +1) and click option = After few seconds when you see result click option: Show steps Then type: integrate (x - x^3) / (x^4 +1) After few seconds when you see result click ...

*March 30, 2012*

**algebra**

m = 0 b = - 4 y = mx + b y = 0 * x + ( - 4 ) y = 0 - 4 y = - 4

*March 30, 2012*

**Math Problem**

c ^ 16 = c ^ 7 * c ^ 9 c ^ 7 / ( c ^ 7 * c ^ 9 ) = 1 / c ^ 9 = c ^ - 9

*March 30, 2012*

**math**

( 1 / 2 ) x + 360 = ( 4 / 5 ) x 360 = ( 4 / 5 ) x - ( 1 / 2 ) x 360 = ( 8 / 10 ) x - ( 5 / 10 ) x 360 = ( 3 / 10 ) x ( 3 / 10 ) x = 360 Multiply both sides by 10 3 x = 360 * 10 3 x = 3600 Divide both sides by 3 x = 3600 / 3 x = 1200 pennies

*March 30, 2012*

**math problem**

- 12 a ^ 2 + 3 a + 3 - ( 6 a ^ 2 + 3 ) = - 12 a ^ 2 + 3 a + 3 - 6 a ^ 2 - 3 = - 12 a ^ 2 - 6 a ^ 2 + 3 a + 3 - 3 = - 18 a ^ 2 + 3 a = 3 a ( - 6 a + 1 ) = 3 a ( 1 - 6 a ) = -3 a ( 6 a - 1 )

*March 30, 2012*

**Math11**

A) 1 / 128 B ) 30 * 128 = 3840 cm = 38.4 m Remark: 1 m = 100 cm 3840 cm / 100 cm = 38.4 m

*March 30, 2012*

**Intermediate Algebra**

2.43 * 10 ^ - 4

*March 30, 2012*

**Tech math**

y = sin ( 2 x + 75 ° ) x = 295 ° y = sin ( 2 * 295 ° + 75 ° ) y = sin ( 590 ° + 75 ° ) y = sin ( 665 ° ) y = sin ( 360 ° + 305 ° ) ------------------------------------ Remark: sin ( 360 ° + theta ) = sin ( theta...

*March 30, 2012*

**Math**

1 revolution = 2 pi radians 450 pi / 2 pi = 225 revolutions

*March 30, 2012*

**Math**

1 2 5 10 17 26 37 50 65 82 If you subtract 1 from every number is should be obvious. 0 1 4 9 16 25 36 64 81 These are the perfect squares. So the answer is: n ^ 2 + 1 Next nunbers : 10 ^ 2 + 1 = 100 + 1 =101 11 ^ 2 + 1 = 121 + 1 = 122 13 ^ 2 + 1 = 169 + 1 = 170 14 ^ 2 + 1 = ...

*March 30, 2012*

**math**

1 - ( 1 / 2 + 1 / 3 ) = 1 - ( 3 / 6 + 2 / 6 ) = 1 - 5 / 6 = 6 / 6 - 5 / 6 = 1 / 6

*March 29, 2012*

**trig**

2 sin ^ 2 ( x ) - 1 = 0 2 sin ^ 2 ( x ) = 1 Divide both sides by 2 sin ^ 2 ( x ) = 1 / 2 sin ( x ) = ± 1 / sqrt ( 2 ) sin ( x ) = 1 / sqrt ( 2 ) for x = pi / 4 and x = 3 pi / 4 sin ( x ) = - 1 / sqrt ( 2 ) for x = 5 pi / 4 and x = 7 pi / 4

*March 29, 2012*

**geometry**

350 * 24 * 30 / ( 8 * 10 ) = 350 * 720 / 80 = 350 * 9 = 3150 $

*March 29, 2012*

**Geometry**

2 / 5 = 7 / x Multiply both sides by x 2 x / 5 = 7 Multiply both sides by 5 2 x = 7 * 5 2 x = 35 Divide both sides by 2 x = 35 / 2 x = 17.5 ft

*March 29, 2012*

**math**

1 h = 60 min 60 / 4 = 15 15 * 52 = 780 miles / hour OR 52 / 4 = 13 miles / min

*March 28, 2012*

**Math**

- 3 y + 5 > 23 - 3 y > 23 - 5 - 3 y > 18 FDivide both sides by - 3 --------------------------------------- Remark : Whenever you multiply or divide an inequality by a negative number, you must reverse the inequality sign. --------------------------------------- y <...

*March 28, 2012*

**trig**

sin ( x ) * tan ( x ) = sin ( x ) * sin ( x ) / cos ( x ) = sin ^ 2 ( x ) / cos ( x )

*March 26, 2012*

**trig**

tan ( x ) = sin ( x ) / cos ( x ) sin ( x ) * tan ( x ) ) sin ( x ) * sin ( x ) / cos ( x ) = sin ^ 2 ( x ) / cos ( x ) cos( x )/ [ sin ( x ) * tan ( x ) ]= cos ( x ) / [ sin ^ 2 ( x ) / cos ( x ) ] = [ cos ( x ) / 1 ] / [ sin ^ 2 ( x ) / cos ( x ) ]= cos ( x ) * cos ( x ) / ...

*March 26, 2012*

**math problem**

In google type: quadratic equation online When you see list of results click on: Free Online Quadratic Equation Solver:Solve by Quadratic Formula When page be open in rectangle type: x ^ 2 + 14 x - 4 = 0 and click option: solve it! You wil see solution step-by-step

*March 26, 2012*

**algebra**

x + y = 38 x - y = 26 - x x + x - y = 26 2 x - y = 26 x - y = 26 - x is equivalet to : 2 x - y = 26 Your system is : x + y = 38 2 x - y = 26 Using Substitution Method. Expressing y as a function of x (from the first equation) x + y = 38 y = 38 - x Substituting this expression ...

*March 25, 2012*

**6th Grade Math**

All your answer is correct.

*March 22, 2012*

**trig**

x = 60 ° cos 60 ° = 1 / 2

*March 22, 2012*

**Calculus**

x1 = 2 x2 = -6 y1 = 3 y2 = 4 Length of first side : a = x1 - x2 a = 2 - ( - 6 ) a = 2 + 6 = 8 Length of second side : b = | ( y1 - y2 ) | b = | 3 - 4 | b = | - 1 | b = 1 P = 2 ( a + b ) P = 2 ( 8 + 1 ) P = 2 * 9 = 18 Remark : | | mean absolute value

*March 22, 2012*

**Match Check**

1 /0.125 = 80

*March 22, 2012*

**ALGEBRA**

Also you can in google type: half-life equation and click : en.wikipedia

*March 21, 2012*

**ALGEBRA**

Equation : N( t ) = N( 0 ) * ( 1 / 2 ) ^ [ t / t( 1 / 2) ] In this case : N ( 30 ) = 480 * ( 1 / 2 ) ^ ( 30 / 10 ) N ( 30 ) = 480 * ( 1 / 2 ) ^ 3 N ( 30 ) = 480 * 1 / 8 = 60 grams

*March 21, 2012*

**ALGEBRA**

After 10 days you have half left After 20 days that's half of the half again = a quarter After 30 days that's half of a quarter = an eighth 480 / 8 = 60 grams

*March 21, 2012*

**Math**

In google type : factor 81a^2 + 36a + 4 When you see lis of results: SOLUTION: Please help, factor the expression 81a^2-36ab+4b^2 ... algebra dotcom/.../Polynomials-and-rational-expressions.faq.questi

*March 21, 2012*

**Calculus**

Go on: wolframalpha dot com When page be open in rectangle type: limit (x-sin(x))/(x-tan(x)) as x->0 and click option = After few seconds when you see result click option: Show steps On wolframalpha dot com you can practice any kind of calculus.

*March 21, 2012*

**math**

A = Area L = Lenght W = Width New lenght L = 125 + x New width W = 75 + x A = W * L A = ( 125 + x ) * ( 75 + x ) A = 75 * 125 + 75 * x + x * 125 + x * x A = 9375 + 75 x + 125 x + x ^ 2 A = x ^ 2 + 200 x + 9375

*March 21, 2012*

**maths**

x / 20 = 0.6 Multiply both sides by 20 20 x / 20 = 0.6 * 20 x = 12

*March 21, 2012*

**geometry**

trapezoid In google type : Only one pair of opposite sides is parallel When you see lis of resuts click on : Quadrilaterals - Square, Rectangle, Rhombus, Trapezoid ...

*March 19, 2012*

**precalc!!!!!**

( a - b ) * ( a ^ 2 + a * b + b ^ 2 ) = a * a ^ 2 + a * a * b + a * b ^ 2 - b * a ^ 2 - b * a * b - b * b ^ 2 = a ^ 3 + a ^ 2 * b + a * b ^ 2 - a ^ 2 * b - a * b ^ 2 - b ^ 3 = a ^ 3 - b ^ 3

*March 19, 2012*

**algebra**

x = - 1 y = - 3 A x – 4 y = 9 A * ( - 1 ) - 4 * ( - 3 ) = 9 - A + 12 = 9 - A = 9 - 12 - A = -3 Multiply both sides by - 1 A = 3 4 x + B y = –1 4 * ( - 1 ) + B * ( - 3 ) = - 1 - 4 - 3 B = - 1 - 3 B = - 1 + 4 - 3 B = 3 Divide both sides by - 3 B = 3 / - 3 B = - 1

*March 18, 2012*

**algebra**

2 x – 3 y = 10 Multiply both sides by 2 4 x - 6 y = 20 5 x + 2 y = 6 Multiply both sides by 3 15 x + 6 y = 18 4 x - 6 y = 20 + 15 x + 6 y = 18 ---------------- 4 x + 15 x - 6 y + 6 y = 20 + 18 19 x = 38 Divide both sides by 19 x = 38 / 19 x = 2 To get the value of y you ...

*March 18, 2012*

**Math**

CORRECTION: ( 2 x ^ 3 ) ^ ( - 3 ) = 2 ^ ( - 3 ) * x ^ [ 3 * ( - 3 ) ] = 2 ^ ( - 3 ) * x ^ ( - 9 ) 1 / ( 2 ^ 3 * x ^ 9 ) = 1 / 8 x ^ 9

*March 18, 2012*

**Math**

( x ^ 2 ) ^ 3 = x ^ 6 ( 2 x ^ 3 ) ^ ( - 3 ) = 2 ^ ( - 3 ) * x ^ [ ( - 3 ) * ( - 3 ) ] = 2 ^ ( - 3 ) * x ^ ( - 9 ) 1 / ( 2 ^ 3 * x ^ 9 ) = 1 / 8 x ^ 9 3 /( 4 x )^ 2 = 3 / ( 4 ^ 2 x ^ 2 ) = 1 / 16 x ^ 2 ( x ^ 2 )^ 3 ( 2 x ^ 3 )^ -3 / ( 4 x ) ^ 2 = x ^ 6 * 1 / 8 x ^ 9 * 1 / 16 x...

*March 18, 2012*

**algebra**

1. 1 h = 60 min 1 h 24 min = 84 min ( 7 / 2 ) * 84 min = 7 * 84 / 2 = 588 / 2 = 294 min 4 h = 4 * 60 = 240 min 294 min = 240 min + 54 min 294 min = 2 h 54 min 2. P = 2 l + 2 w P - 2 l = 2 w 2 w = P - 2 l Divide both sides by 2 w = ( P - 2 l ) / 2 OR w = ( P / 2 ) - l

*March 18, 2012*

**Math 2**

x = - 3 , y = 8 QUADRANT II arc tan ( sqrt 73 ) = 83.324408° tan ( theta ) = - sqrt ( 73 ) theta = 180 ° - 83.324408° theta = 96.675592° theta = 96° 40' 32"

*March 18, 2012*

**Math(Please check)**

If you must simplify your answer: x ^ 2 = 106.4 / 2.5 * ( 10 / 10 ) x ^ 2 = 1064 / 25 x ^ 2 = 4 * 266 / 25 x = sqrt ( 4 * 266 / 25 ) x = ± (2 / 5 ) * sqrt ( 266 )

*March 18, 2012*

**Math(Please check)**

2.5 * 10 ^ ( - 3) = ( 0.28 ) * ( 0.38 ) / x ^ 2 Multiply both sides by x ^ 2 2.5 * 10 ^ ( - 3) * x ^ 2 = ( 0.28 ) * ( 0.38 ) 2.5 * 10 ^ ( - 3) * x ^ 2 = 0.1064 Divide both sides by 2.5 * 10 ^ ( - 3) x ^ 2 = 0.1064 / 2.5 * 10 ^ ( - 3) x ^ 2 = 0.1064 * 10 ^ 3 / 2.5 Remark: 1 / ...

*March 18, 2012*

**Math help**

Not necessary. x intercept - 4 x - 3 = 0 - 4 x = 3 Divide both sides by - 4 x = - 3 / 4 A line passing through points : x = - 3 / 4 , y = 0 and x = 0 , y = - 3

*March 18, 2012*

**Math help**

In this case : slope = - 4 y intercept = - 3 In google type: functions graphs online When you see list of results click on: rechneronline.de/function-graphs/ When page be open in blue rectangle type: -4x-3 And click option: Draw

*March 18, 2012*

**precalc!!!!!**

Go on calc 101 dot com When page be open click option : long division

*March 18, 2012*

**pre-calculus**

In google type : r=3cos2theta When you see list of results click on : Advanced Math: precal, trig identities, conversion You will see answer.

*March 18, 2012*

**Algebra**

Line x = 1 are parallel with y-axis and passing through point x = 1 The angle theta a line makes with the positive x axis is closely related to the slope m via the tangent function: m = tan ( theta ) In this case theta = 90 ° tan 90 ° = infinity Slope of line x = 1 m...

*March 18, 2012*

**Algebra**

y = m x + b m = slope b = y-intercept In this case : slope m = 5 / 3 y-intercept = - 3 y = ( 5 / 3 ) x + ( - 3 ) y = ( 5 / 3 ) x - 3

*March 18, 2012*

**algebra 2**

A = Area of the printed matter w = width a = 10 - 2 w b = 18 - 2 w ( 10 - 2 w ) * ( 18 - 2 w ) = A 18 * 10 - 18 * 2 w - 2 w * 10 - 2 w * ( - 2 w ) = A 180 - 36 w - 20 w + 4 w ^ 2 = A 4 w ^ 2 - 56 w + 180 - A = 0 Are you sre that the printed matter of a book must cover 0 cm ^ 2 ?

*March 18, 2012*

**algebra 2**

A = Area b = base h = height h = b + 3 A = b * h / 2 = 189 ft ^ 2 b * h / 2 = b * ( b + 3 ) / 2 = 189 Multiply both sides by 2 b * ( b + 3 ) = 378 b ^ 2 + 3 b - 378 = 0 The solutions are : b = 18 ft and b = - 21 ft The base can't be negative,so solution are : b = 18 ft h...

*March 18, 2012*

**Algebra1**

1 ft = 12 in 1 ft ^ 2 = ( 12 ^ 2 ) in ^ 2 1 ft ^ 2 = 144 in ^ 2 15 * 144 = 2160 15 ft ^ 2 = 2160 in ^ 2 2160 / 180 = 12 12 hours

*March 18, 2012*

**algebra**

Two point form of linear equation : y - y 1 = ( y 2 - y 1 ) * ( x - x 1 ) / ( x 2 - x 1 ) Te slope is explicitly given as m = ( y 2 - y 1) / ( x 2 - x 1 ) In this case : x 1 = - 2 x 2 = 3 y 1 = 8 y 2 = 5 m = ( y 2 - y 1 ) / ( x 2 - x 1 ) m = ( 5 - 8 ) / [ 3 - ( - 2 ) ] m = - 3...

*March 18, 2012*

**Math**

Factorisation : 4356 = 2 * 2 * 3 * 3 * 11 * 11 60 = 2 * 2 * 3 * 5 4356 / 60 = 2 * 2 * 3 * 3 * 11 * 11 / ( 2 * 2 * 3 * 5 ) = 3 * 11 * 11 / 5 = 363 / 5 = 72.6

*March 18, 2012*

**MAT/116**

- 1 + ( - 6) = - 1 - 6 = -7

*March 17, 2012*

**Algebra**

CORRECTION : When page be open in blue rectangle type: x ^ 2 - 55 x + 650 Set: Range x-axis from - 20 to 80 Range y-axis from - 200 to 800 And click option: Draw

*March 16, 2012*

**Algebra**

If you must draw function : L ^ 2 - 55 L + 650 = 0 In google type: functions graphs online When you see list of results click on: rechneronline.de/function-graphs/ When page be open in blue rectangle type: x ^ 2 - 55 x + 650 = 0 Set: Range x-axis from - 20 to 80 Range y-axis ...

*March 16, 2012*