Question

A rectangular garden is 8 metres longer than it is wide. if its area is 240m2 , how many metres is the width (ie. the shortest side)?

Answer 1

Area of a rectangle is length by width, width is x, length is x+8
x×(x+8)=240
x²+8x=240
x²+8x-240=0
Use the quadratic formula to solve
$x=\frac{-b±\sqrt{b^{2}-4ac}}{2a} x=\frac{-8±\sqrt{8^{2}-4(1)(-240)}}{2(1)} x=\frac{-8±\sqrt{64-4(-240)}}{2}$$x=\frac{-8±\sqrt{1024}}{2} x=\frac{-8±32}{2} x=\frac{24}{2} OR \frac{-40}{2} x=12 OR -20$
It is a distance so can't be negative, so the answer must be 12