G(a)=3a-2
find g(-9)
help!

G(a)=3a-2 says “take your input (a) and multiply it by 3 and then subtract 2.”

g(-9) tells you that your input will be -9, so apply the rule given above to -9: multiply it by 3 and subtract 2.

g(-9) = 3(-9) - 2

And then finish by cleaning up the right side using order of operations.