find the following product

7z (3z^3 - 2z+ 4)

7z (3z^3-2z+4)= 21z^4-14z^2+28z i could show you much better vertically, but i can'tmake the curser go where i want nor can i print the numbers on the line that i want, but you simply mult each factor in each term, in this case one term, by each factor in every other term one time only.