I don't understand how to do this. Can somebody please help me? I can't figure out how to do this, and I don't see any instructions in my lesson. Thank you in advance.
(-4x) x 9x^2
since multiplication is commutative, just shuffle things around a bit.
(-4x)(9x^2)
-4 * x * 9 * x^2
-4*9 * x*x^2
-36x^3
PS -- it helps if you don't use "x" for both multiplication and a variable name.