Question

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

Answer 1

Answer:

(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

Step-by-step 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.