22/2=11
11^2=121, or C, would complete the square
F(x) = -9x^2 + 7x + 2
Factorising we get:
f(x) = (x + 1) (-9x + 2)
The solutions are x = -1 and 2/9ths
Proving the converse of the Pythagorean Theorem means proving that if the <u>sum</u> of the squares of the lengths of the <u>shorter</u> sides of a triangle equals the square of the length of the <u>longest</u> side, then the triangle is a right angle triangle.
Here's the equation:
(short side)² + (short side)² = (long side)²