Find the sum.

7x + 15x=

7x + 15x = 21x

Step-by-step explanation:

7x + 15x

= (7 + 15) x

= 22x

Answer: 22x

Step-by-step explanation: + 7x and + 15x are called terms and the numbers in front of the variables, + 7 and + 15 are called coefficients.

Because the variables, x and x, are identical, the two terms in this problem are called like terms. Like terms can be added together by simply adding their coefficients. So in this problem, since 7 + 15 is 22, 7x + 15x is simply 22x.