Thread: Pythagorean theorem?

How much is x?

Originally Posted by Nforce

How much is x?

(x - 3)^2 + x^2 = (x + 3)^2.

Expand, simplify and solve for x.

i know i have to use pythagorean theorem, but i can's solve it. I always get x^2 = 12x

Originally Posted by Nforce

i know i have to use pythagorean theorem, but i can's solve it. I always get x^2 = 12x

x^2 - 12x = 0 => x(x - 12) = 0 => x = 0 (rejected) or x = 12.

yes, thanks... i forget that