Question

PLSS HELP

Solve each system using SUBSTITUTION. Remember to check!



2) y = –2x – 1

y = 3x – 16

Answer 1

(3, -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

• Solving systems of equations using substitution/elimination
• Solving systems of equations by graphing

Explanation:

Step 1: Define Systems

y = -2x - 1

y = 3x - 16

Step 2: Solve for x

Substitution

1. Substitute in y: -2x - 1 = 3x - 16
2. Add 2x on both sides: -1 = 5x - 16
3. Add 16 on both sides: 15 = 5x
4. Divide 5 on both sides: 3 = x
5. Rewrite: x = 3

Step 3: Solve for y

1. Define equation: y = -2x - 1
2. Substitute in x: y = -2(3) - 1
3. Multiply: y = -6 - 1
4. Subtract: y = -7

Step 4: Graph Systems

We can check the solution set to the systems of equations.

Where the 2 lines intersect is the solution set to the systems of equations.

The 2 lines and our algebraically solved solution sets are the same.