Question

How do you multiply binomials by a binomial

Answer 1

FOIL!!!!!!

F: first
O: outer
I: inner
L: last

multiply the first terms in each set of parenthesis together
multiply the outer most terms together
multiply the inner most terms together
multiply the last terms in each set of parenthesis

Here's an example

(x + 5)(x - 2)

F: first
- multiply the first terms in each set of parenthesis together

x · x = x²

O: outer
- multiply the outer most terms together

x · -2 = -2x

I: inner
- multiply the inner most terms together

5 · x = 5x

L: last
- multiply the last terms in each set of parenthesis

5 · -2 = -10

x² - 2x + 5x - 10

Combine like terms

-2x + 5x = 3x

x² + 3x -10 is the answer

I hope this helps

Answer 2

there are a couple of ways....

(3x + 4)(2x + 5).....using FOIL (first,outside,inside,last)
F -- multiply first terms in each set.....3x * 2x = 6x^2
O -- multiply outside terms in each set...3x * 5 = 15x
I -- multiply inside terms in each set....4 * 2x = 8x
L -- multiply last terms in each set...4 * 5 = 20
now we have
6x^2 + 15x + 8x + 20
combine like terms
6x^2 + 23x + 20 <===

or this way...
(3x + 4)(2x + 5)...distribute the 3x through the parenthesis, and then the 4 through the parenthesis...
3x(2x + 5) + 4(2x + 5) = 6x^2 + 15x + 8x + 20 = 6x^2 + 23x + 20 <==