The altitude of a triangle is 6 cm greater than its base .if its area is 108 cm ,find its base

Area of the triangle = (1/2)*base*height

base = x

height = altitude = x+6

Area of the triangle = (1/2)*x*(x+6) = 108

(1/2)*x*(x+6) = 108

x²+6x-216 =0

(x+18)(x-12)=0

x=-18, or x=12

We can use only positive value, so x=12.

Base =12 cm.

- 2 + 10x³ - 21x² + 19x - 4

step-by-step explanation:

each term in the second factor is multiplied by each term in the first factor

x²(- 2x² + 4x - 1) - 3x(- 2x² + 4x - 1) + 4(- 2x² + 4x - 1) ← distribute

= - 2 + 4x³ - x² + 6x³ - 12x² + 3x -8x² + 16x - 4

collect like terms

= - 2 + 10x³ - 21x² + 19x - 4 ← in standard form