One student rewrote the expression as, and then simplified to get the expression a.) are the three expressions equivalent? justify your answer. b.)what property of numbers does this demonstrate?

hello,

as   long as they add up to 180 its correct.

answer is b.

15

i got this one as well.

  d. △abc is congruent to △fde

step-by-step explanation:

triangle abc is reflected across the x-axis. the corresponding vertices are

the names of the triangles in the congruence statement must have corresponding vertices in the same order. that is, △abc is congruent to △fde.