SOLUTION: The length and breadth of a rectangle are (2x+5)cm and ( 2x-1) cm respectively. The areabof rectangle is three times the area of square (x+1)cm. Form an equation in x and show th

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: The length and breadth of a rectangle are (2x+5)cm and ( 2x-1) cm respectively. The areabof rectangle is three times the area of square (x+1)cm. Form an equation in x and show th      Log On


   

Question 1146135: The length and breadth of a rectangle are (2x+5)cm and ( 2x-1) cm respectively. The areabof rectangle is three times the area of square (x+1)cm.
Form an equation in x and show that is reduces to x^2+2x-8=0
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

if the length and breadth of a rectangle are %282x%2B5%29cm and %28+2x-1%29cm respectively, the area of rectangle is
%282x%2B5%29%2A%28+2x-1%29
the area of square %28x%2B1%29cm is %28x%2B1%29%5E2
the area of rectangle is three times the area of square %28x%2B1%29cm, we have
%282x%2B5%29%2A%28+2x-1%29=3%28x%2B1%29%5E2......simplify
%282x%2B5%29%2A%28+2x-1%29=3%28x%2B1%29%5E2
4x%5E2+%2B+8x+-+5=3%28x%5E2%2B2x%2B1%29
4x%5E2+%2B+8x+-+5=3x%5E2%2B6x%2B3
4x%5E2+%2B+8x+-+5-3x%5E2-6x-3=0

x%5E2+%2B+2x+-+8=0 => shows that is reduces to x%5E2%2B2x-8=0