solve 3x²+8x+7x

A) 3x² + 15x

B) 18x3

C) 3x²+1

D) 3x²-x

Combining like terms, we get:

3x² + 8x + 7x = 3x² + 15x

Therefore, the answer is A) 3x² + 15x.

To simplify the expression 3x² + 8x + 7x, we combine the like terms.

Combining the terms 8x and 7x, we get 15x.

Therefore, the simplified expression is 3x² + 15x.

Therefore, the correct option is A) 3x² + 15x.