A triangle has an area of 120 sq units. Need to find the base and the height.

Question

120=1/2(3x+9)(x=5)

Answer 1

The 65 comes about by dividing each side of the prior version of the equation by three.

Then the quadratic was FACTORED.

Factoring is a really important skill--you'll need to master it because algebra permeates the entire high school experience, and also some of the academic experience beyond high school.

 

Answer 2

120=(1/2)(3x+9)(x+5)

240=(3x+9)(x+5)

240=3x^2+9x+15x+45

240=3x^2+24x+45

3x^2+24x+45-240=0

3x^2+24x-195

x^2+8x-65=0

(x+13)(x-5)=0

x-5=0

x=5

3x+9=24 units and x+5=10 units; either one can be the base and the other the height

A=1/2 * 24 * 10

A=1/2 * 240

A=120