To add or subtract terms with exponents, both the base and the exponent must be the same. If the base and the exponent are the same, add or subtract the coefficients and retain the base and exponent. For example, 3x2 + 2x2 = 5x2 and 3x2 - 2x2 = x2 but x2 + x4 and x4 - x2 cannot be combined.
What is 7y2 + 2y2?
| 9y2 | |
| 5y2 | |
| 9y4 | |
| 5y-2 |