Pre-Algebra
Unit 4: Linear Equations
Introduction to Two-Column Proofs
Name:
Worksheet 4.2
Solve each equation and justify your answer using a two-column proof.
1.
Statement
1. -2x + 7 = 5
2. -2x + 7 – 7 = 5 – 7
3. -2x = -2
4.
2.
3. Subtraction fact
4. Division Property of Equality
Statement
1. 3x – 10 = -4
2.
1. Given
2. Addition Property of Equality
3. 3x = 6
4.
3.
4.
5. x = 2
5.
3.
4. 7 – 9x = 79
1. Given
5. Division fact
5.
2.
Reason
Reason
Statement
Reason
1. 9 + = -3
1. Given
2.
2.
3.
3.
4.
4.
5.
5.
5. 3(x – 6) + 1 = -11