B. 11.33 is closer to the area of a circle with a radius of 2.1
x + 4 = 12 Subtract 4 on both sides to get "x" by itself
x + 4 - 4 = 12 - 4
x = 8
You would divide 10 into 477 to get 47.7, but you can't put 47.7 because you can't have a decimal. The answer is 47
81 is a counter example of the conditional statement given.
81 has factors other than itself, 1 and the square root of 81 which is 9.
81 has factors of 3 and 27 which are not listed.