What does DB equal in this triagle?​

Hello people, i have a math question that i need with, me, i will give the correct one brainiest, and for the other correct people, a and 5 stars.

If f(x) =3x-2 and g(x) =2x+1 fins (f+ g) (x)

Atriangle has an area of 72 square inches. if the base of the triangle has a length of 18 inches, what is the height of the triangle? use the formula for the area of a triangle: area = (base)(height) type a numerical answer in the space provided. do not include the units or spaces in your answer.