Are the situation 3,5,8, and 10 different from the situation in 1,2,4,6,7 and 9? how?

Solve this problem! extra ! 3025/5.5 = a/90.75

1. ∠1 is complementary to ∠2 and ∠3 is complementary to ∠2. subtraction property of equality 2. m∠1 + m∠2 = 90 and m∠3 + m∠2 = 90 substitution 3. m∠1 + m∠2 = m∠3 + m∠2 definition of complementary 4. m∠1 = m∠3 given

Which statement best describes how to determine whether f(x) = x squared- x +8 is an even function ?