Answer:
1) Given
2) Definition of Midpoint
4) Substitution PoE
5) 4x=16
6) Divison PoE
Step-by-step explanation:
1) is given because it is given.
2) Should be definition of midpoint because a midpoint bisects a line, meaning both sides are congruent.
4) is substitution because, like aforementioned, AC=6x and CD=2x+16, so substitute those numbers in the equation.
5) is 4x=16 because that's what happens when you subtract 6x-2x.
6) should be division PoE because to isolate x you need to divide by 4.
