Answer:
(-3, 3)
General Formulas and Concepts:
Pre-Algebra
- Order of Operations: BPEMDAS
- Equality Properties
Algebra I
- Solving systems of equations using substitution/elimination
Step-by-step explanation:
Step 1: Define systems
-5x - y = 12
y = -4x - 9
Step 2: Solve for x
Substitution
- Substitute in y: -5x - (-4x - 9) = 12
- Distribute negative: -5x + 4x + 9 = 12
- Combine like terms: -x + 9 = 12
- Subtract 9 on both sides: -x = 3
- Divide -1 on both sides: x = -3
Step 3: Solve for y
- Define original equation: y = -4x - 9
- Substitute in x: y = -4(-3) - 9
- Multiply: y = 12 - 9
- Subtract: y = 3
