Question

Substation method
3x + 4y=-22
7x+y=7

Answer 1

(2, -7)

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

• Multiplication Property of Equality
• Division Property of Equality
• Addition Property of Equality
• Subtract Property of Equality

Algebra I

• Terms/Coefficients
• Solving systems of equations using substitution/elimination

Explanation:

Step 1: Define Systems

3x + 4y = -22

7x + y = 7

Step 2: Rewrite Systems

7x + y = 7

1. Subtract 7x on both sides: y = 7 - 7x

Step 3: Redefine Systems

3x + 4y = -22

y = 7 - 7x

Step 4: Solve for x

Substitution

1. Substitute in y: 3x + 4(7 - 7x) = -22
2. Distribute 4: 3x + 28 - 28x = -22
3. Combine like terms: -25x + 28 = -22
4. Subtract 28 on both sides: -25x = -50
5. Divide -25 on both sides: x = 2

Step 5: Solve for y

1. Define equation: 7x + y = 7
2. Substitute in x: 7(2) + y = 7
3. Multiply: 14 + y = 7
4. Subtract 14 on both sides: y = -7