Final answer:
The equivalent expression to 9x - 2x + 3 is 3 + 7x, because like terms have been combined, giving us 7x + 3.
Step-by-step explanation:
The expression 9x - 2x + 3 can be simplified by combining like terms. Here, 9x and -2x are like terms because they both contain the variable x to the same power. To simplify, we subtract 2x from 9x, which gives us 7x. Then we bring down the constant +3. The simplified expression is 7x + 3, which can also be written as 3 + 7x. So the equivalent expression to 9x - 2x + 3 is 3 + 7x.