integer n squares

by **larhea** Mon Nov 17, 2008 8:57 pm

The sum of an integer and its square (that integer multiplied times itself) is 132. What could that integer be?

by **Guest** Mon Nov 17, 2008 10:09 pm

Just try different numbers. 11 is the answer: 11+121=132

by RR Tue Nov 18, 2008 2:18 pm

Let the integer be x
Therefore square of the integer is x^2

x^2 + x = 132
x^2 + x - 132 = 0
Solve for x
(x + 12)(x - 11) = 0
x = -12 or x = 11

by **RonPurewal** Sat Nov 29, 2008 8:12 am

"just try different numbers" is the more efficient way to go here, especially since it's not at all difficult to guess the size of the required number.

this is not a GMATPREP problem, so i've moved it to the general math folder.