Write a two-column proof.
Given: 7y = 8x - 14; y = 6
Prove: x = 7
Statements | Reasons
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1. 7y = 8x - 14 | Given
2. 7(6) = 8x - 14 | Substitution Property of Equality
3. 42 = 8x - 14 | Simplify
4. 42 + 14 = 8x | Addition Property of Equality
5. 56 = 8x | Simplify
6. 56/8 = x | Division Property of Equality
7. 7 = x | Simplify
Statement | Reason
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1. 7y = 8x - 14 | Given
2. y = 6 | Given
3. 7(6) = 8x - 14 | Substitution (from statements 1 and 2)
4. 42 = 8x - 14 | Simplification
5. 56 = 8x | Addition by 14 on both sides
6. x = 7 | Division by 8 on both sides (after simplifying)