Question

Solve by substitution x-7y=7 6x-7y=-28

Answer 1

(-7, -2)

General Formulas and Concepts:

Pre-Algebra

• Order of Operations: BPEMDAS
• Equality Properties

Algebra I

• Solving systems of equations using substitution/elimination

Explanation:

Step 1: Define systems

x - 7y = 7

6x - 7y = -28

Step 2: Rewrite systems

x = 7y + 7

6x - 7y = -28

Step 3: Solve for y

1. Substitute: 6(7y + 7) - 7y = -28
2. Distribute 6: 42y + 42 - 7y = -28
3. Combine like terms: 35y + 42 = -28
4. Isolate y term: 35y = -70
5. Isolate y: y = -2

Step 4: Solve for x

1. Define original equation: x - 7y = 7
2. Substitute in y: x - 7(-2) = 7
3. Multiply: x + 14 = 7
4. Isolate x: x = -7

And we have our answer!