Question

12x² + 9x² =
A. 21x²²
B. 21x
C. 22x²
D. 22xA

Answer 1

Answer: A (if it's just a typo) or
`21x^(2)`

Explanation:

Since it's the same variable and same exponent, you just need to add the whole numbers and put the same variable and exponent.

12 + 9 = 21

`21x^(2)`

Answer 2

21x²

Explanation:

hopefully A is a typo