6 xD
And kia:
2x + 24 -3(2x + 4)= -4
2x -6x=-4-24-12
-4x=-40
x= 10
you got your 12 wrong...it's -12, so bringing it over makes it +12...
-4-24+12=-16
-4x=-16
x=4
and i like this:
7i^4
gotta love i^4 lol...
anyways:
∫(4x^3 + 5x^2 + 3x +18) dx = 16119/2
gotta keep it easy, right?