SOLUTION: given area of a triangle is 36 inches squared, base 3x inches, height 2x+2 inches, Prove: solve for x and find the base. I totally don't get this or even know where to start!

Algebra ->  Geometry-proofs -> SOLUTION: given area of a triangle is 36 inches squared, base 3x inches, height 2x+2 inches, Prove: solve for x and find the base. I totally don't get this or even know where to start!      Log On


   

Question 706004: given area of a triangle is 36 inches squared, base 3x inches, height 2x+2 inches, Prove: solve for x and find the base.
I totally don't get this or even know where to start!
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
given area of a triangle is 36 inches squared, base 3x inches, height 2x+2 inches, Prove: solve for x and find the base.
:
You know (hopefully) the area of a triangle: A = 1%2F2*b*h
therefore:
1%2F2*(3x)*(2x+2) = 36
get rid of the fraction, mult both sides by 2
3x(2x+2) = 72
6x^2 + 6x - 72 = 0
a quadratic equation that we an simplify, divide by 6
x^2 + x - 12 = 0
Factors to
(x+4)(x-3) = 0
the positive solution
x = 3
:
:
You can prove this to yourself, replace x with 3 in each expression and find the area