geometry from gmatprep

[smallsorrow]

A square playground has the same area as a rectangular playground that is 30 feet longer but 20 feet narrower. What is the length, in feet, of a side of the square playground?
A) 10 radical 5
B) 10 radical 6
C) 25
D) 50
E) 60

Is there a way to avoid the quadratic equation?

[stop@800]

yes

s2 will cancel out and thr will not be any quadretic

a*a = (a+30)(a-20)
solve it
a = 60 [a^2 on both sides will cancel out]

[smallsorrow]

Ah ... Get it - did not see it this afternoon! Thanks!

[vishubn]

yes,
kinda straight....

area of a sq=area of rect

L*L=(L+30)(L-20)
L^2=L^2-20L+30L-600
-20L+30L-600=0
L=60

Hope this helps

Vishu