Respuesta :

mhanifa

Step-by-step explanation:

#1

  • a + 10 = 20 ⇒ subtract 10 form both sides ⇒ a = 10
  • Subtraction property of equality

#2

  • 4x - 5 = x + 12 ⇒ add 5 to both sides ⇒ 4x = x + 17
  • Addition property of equality

#3

  • 5(x + 7) = -3 ⇒ multiply 5 to both terms ⇒ 5x + 35 = - 3
  • Distributive property of multiplication

#4

  • If AB = BC and BC = CD, then AB = CD
  • Transitive property of equality