Question

Given: 2x + 4 = 1 – 2x – 5
Prove: x = –2
Given the equation 2x + 4 = 1 – 2x – 5, use the commutative property to rearrange the terms so that like terms are next to one another. This gives the equation 2x + 4 = 1 – 5 – 2x. Then, use the associative property of addition to group the like terms. This gives the equation 2x + 4 = (1 – 5) – 2x. Next, combine like terms to get the equation 2x + 4 = –4 – 2x. Use the ___________________ to add 2x to both sides of the equation. This gives the equation 4x + 4 = –4. Then use the subtraction property of equality to subtract 4 from both sides of

Answer 1

sides of the equation. This gives the equation 4x = –8. Finally, use the division property of equality to divide both sides of the equation by 4 to give a final solution of x = –2. Therefore, given 2x + 4 = 1 – 2x – 5, x is equal to –2.

Which justification was left out of the paragraph proof above?
Answer
Associative Property of Addition
Subtraction Property of Equality
Addition Property of Equality
Commutative Property of Subtraction