# 30? (Algebra help)?

a) (2x+1)^2=x^2+(x+7)^2
4x^2+4x+1=2x^2+14x+49
2x^2-10x-48 = 0
x^2-5x-24 = 0
(x+3)(x-8) = 0
x = 8 ft
sides are 8 ft, 15 ft and 17 ft
b) b) z^2 = 15^2-9^2
z = 12 ft
9 ft, 12 ft and 15 ft

Pythagoras - x^2 + (x+7)^2 = (2x+1)^2
Therefore 2x^2 + 14x +49 = 4x^2 + 4x +1
2x^2 - 10x - 48 = 0
X^2 - 5x - 24 = 0
(X+3)(x-8)=0
So x = 8.
Sides are 8, 17 and 15.
Do pythag again for the length of the other triangle