Question

Solve by the substitution method.
6x + 8y = 0
-7x + y = 31

Answer 1

(-4, 3)

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

1. Brackets
2. Parenthesis
3. Exponents
4. Multiplication
5. Division
6. Addition
7. Subtraction

• Left to Right

Equality Properties

Algebra I

• Solving systems of equations using substitution/elimination

Explanation:

Step 1: Define Systems

6x + 8y = 0

-7x + y = 31

Step 2: Rewrite Systems

-7x + y = 31

1. Add 7x to both sides: y = 7x + 31

Step 3: Redefine Systems

6x + 8y = 0

y = 7x + 31

Step 4: Solve for x

Substitution

1. Substitute in y: 6x + 8(7x + 31) = 0
2. Distribute 8: 6x + 56x + 248 = 0
3. Combine like terms: 62x + 248 = 0
4. Isolate x term: 62x = -248
5. Isolate x: x = -4

Step 4: Solve for y

1. Define equation: -7x + y = 31
2. Substitute in x: -7(-4) + y = 31
3. Multiply: 28 + y = 31
4. Isolate y: y = 3