SOLUTION: The length of a rectangle is 9cm mor than its width. If the area of the rectangle is 76cm^2, find the dimensions. Round to the nearest thousandth if necessary.

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equation Customizable Word Problems -> SOLUTION: The length of a rectangle is 9cm mor than its width. If the area of the rectangle is 76cm^2, find the dimensions. Round to the nearest thousandth if necessary.      Log On


   

Question 328716: The length of a rectangle is 9cm mor than its width. If the area of the rectangle is 76cm^2, find the dimensions. Round to the nearest thousandth if necessary.
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
let width be x cm
length = x+9 cm
Area = 76 cm^2
Area = L*W
x(x+9)=76
x^2+9x=76
x^2+9x-76=0
find the roots of the equation x1 x2
x1=%28-b%2Bsqrt%28b%5E2-4%2Aa%2Ac%29%29%2F%282%2Aa%29
x1=%28-9%2Bsqrt%2881-4%2A1%2A%28-76%29%29%29%2F%282%2A1%29
x1=5.311 cm width
x2=%28-9-sqrt%2881-4%2A1%2A%28-76%29%29%29%2F%282%2A1%29
=-14.31 cm ignore this value
length = 5.311+9=14.311 cm