Question

Please help me solve? (m3n + 8)(m3n - 5) multiplying polynomial by polynomial

Answer 1

The final result should be $m^{6}n^{2} - 3m^{3}n - 40$.

In order to multiply any polynomials, use the pattern FOIL (which stands for first, outer, inner, last). You multiply what they ask you to at each step.

First - The first terms in both parenthesis.

$m^{3}n * m^{3}n = m^{6}n^{2}$

Outer - The terms on the outside of both parenthesis.

$m^{3}n * -5 = -5m^{3}n$

Inner - The terms on the inside of both parenthesis.

$m^{3}n * 8 = 8m^{3}n$

Last - the last numbers in each parenthesis.

8 * - 5 = - 40

Now we put all the answers together and simplify like terms,

$m^{6}n^{2} + -5m^{3}n + 8m^{3}n - 40$

$m^{6}n^{2} - 3m^{3}n - 40$