diketahui f(x)=3x1 , g(x) = x²-2x-3 dan h(x)= 2x+1. tentukan a.(gohof)(-3) b.(fogoh)(-3)

a. g o h = g(h(x)) (g o h) o f(-3)
=g(2x+1) = (g o h) (3x+1)
=(2x+1)²-2(2x+1)-3 =4(3x+1)²-5
=4x²+4x-4x-2-3 =4+9x²+6x+1-5
=4x²-5 =4+9x²+6x-4
=9x²+6x+4-4
=9x²+6x=9(-3)²+6(-3)
=81-18=63