#5 Test question 7th grade math

If anyone has done the algebra 2 chaos theory portfolio would you be wiling to me? i kind of know what i'm doing i just don't know if i'm doing it right.

If x = -2, then x 2-7x+10 equals a. 0 b.20 c.28

Use the formulas a = x 2 – y 2, b = 2xy, c = x 2 + y 2 to answer this question. one leg of a right triangle has length 11 and all sides are whole numbers. find the lengths of the other two sides. the other leg = a0 and the hypotenuse = a1