SOLUTION: The length of a rectangle is 7 more than the width. The area is 800 square centimeters. Find the length and width of the rectangle. Using the applications of quadratic equations

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Question 975803: The length of a rectangle is 7 more than the width. The area is 800 square centimeters. Find the length and width of the rectangle. Using the applications of quadratic equations
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
W=x
L=x+7
x(x+7)=700 sq cm
x^2+7x-700=0
x=(1/2) * -7 +/- sqrt (49+2800)
sqrt(2849)=53.376
x=(1/2) [-7+53.376]; negative root not significant
graph%28300%2C300%2C-10%2C30%2C-100%2C800%2Cx%5E2%2B7x-700%29
x=0.5* 46.376= 23.188 cm
x+7=30.188 cm
product of two is 700 sq cm
graph%28300%2C300%2C-50%2C50%2C-1000%2C1000%2Cx%5E2%2B7x-700%29