Please help with problem

Question

7x^2-3x-4

x 5x+1

Answer 1

I find it easy to use a rectangle to do these sorts of multiplications just because it forces me to stay more organized. Put one polynomial along the top and another along the side and multiply each "pair" in the intersecting box. Like this:

Then just combine like terms from the 6 boxes to get:

35x³ - 8x² - 23x - 4