Question

-3x + 10y = 11
-8x + 2y = -20

Answer 1

(3, 2)

General Formulas and Concepts:

Pre-Algebra

• Order of Operations: BPEMDAS
• Equality Properties

Algebra I

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

Explanation:

Step 1: Define systems

-3x + 10y = 11

-8x + 2y = -20

Step 2: Rewrite systems

-8x + 2y = -20

1. Add 8x to both sides: 2y = 8x - 20
2. Divide 2 on both sides: y = 4x - 10

Step 3: Redefine systems

-3x + 10y = 11

y = 4x - 10

Step 4: Solve for x

Substitution

1. Substitute in y: -3x + 10(4x - 10) = 11
2. Distribute 10: -3x + 40x - 100 = 11
3. Combine like terms: 37x - 100 = 11
4. Add 100 to both sides: 37x = 111
5. Divide 37 on both sides: x = 3

Step 5: Solve for y

1. Define original equation: -3x + 10y = 11
2. Substitute in x: -3(3) + 10y = 11
3. Multiply: -9 + 10y = 11
4. Add 9 to both sides: 10y = 20
5. Divide 10 on both sides: y = 2

Step 6: Graph system

Check the system.