Answer:
the digit two is in tens... so a) is the answer
Your radius would have to be 1.91
I want to answer this, but I can't tell what the picture is. (please take a better photo)
You apply the rule to put the exponent in front, and lower it by one. But since this is a nested expression, you apply it twice:
4*(5x^3-4)^3 * 3*5x^2 =
60x^2 (5x^3-4)^3