I need help waht is the correct answer ?
There is a number of ways that this can be done.
If you are a junior student then
I suggest that you multiply (1+h)(1+h)
then mulpiply the answer by (1+h)
then multply that answer by -2
-2*(1+h)3=-2*(1+h)*(1+h)*(1+h)
=-2*(1+h+h+h2)*(1+h)
=-2*(1+2h+h2)*(1+h)
=-2*(1+h+2h+2h2+h2+h3)
=-2*(1+3h+3h2+h3)
=-2-6h-6h2-2h3