please answer this and explain I'm having a hard time understanding this

Answer:
Step-by-step explanation:
Statement
1 .
m<ACB = 2(x+10)
m <DCE = 5(3x-74)
2. <ABC ≅ <DCE
3. <ABC = <DCE
4. 2(x+10) = 5(3x-74)
5. 2x+20 = 15x -370
6. -13x = -390
7. x = 30
8. m<ACB = 2(30+10)°
9. m<ACB =80
Reason
1. Given
2. Vertical angles are congruent
3. Congruent angles have equal measure
4. Substitution POE (postulate of equivalence)
5. Distributive property of multiplication over addition and subtraction
6. - POE (subtraction POE- because we subtracted the same amount from both sides of the equation 15x and 20 )
7. division POE (we divided both sides of the equation by -13)
8. Substitution Postulate (we substituted x for 30)
9. Addition and multiplication postulate