Answer:
C
Step-by-step explanation:
We can notice the expression is the special product a^2 - b^2, which can be factored into (a + b)(a - b). By correlating the expression with the formula, we can say:
a^2 = 9r^2
-and-
b^2 = 100s^2t^2
Therefore:
a = 3r
-and-
b = 10st
Now we can substitute these values into the factored form, (a + b)(a - b):
(3r + 10st)(3r - 10st)
This is the same as option C, meaning C is the answer.
