Which expression is equivalent to 9^-2?
–81
–18
1/81
1/18

(C)

Step-by-step explanation:

The given expression is:

Upon solving the above expression, which can be written as:

which is same as the expression given in the option (C) that is , hence the option C is correct.

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.