Question

the length of a rectangle is 4 meters less than twice its width. The area of the rectangle is 70m2. Find the dimensions of the rectangle

Answer 1

If the width = x m then the length =  2x - 4 m

Area =  x(2x - 4) = 70

2x^2 - 4x - 70 = 0

2x^2 - 14x + 10x - 70 = 0

2x(x - 7) + 10(x - 7) = 0

(2x + 10)(x - 7) = 0
x = 7 or -5  ( ignore negative)
width = 7 m and length = 10 m  answer