Answer:
(5, 9)
General Formulas and Concepts:
Pre-Algebra
Order of Operations: BPEMDAS 
- Brackets 
 - Parenthesis 
 - Exponents 
 - Multiplication 
 - Division 
 - Addition 
 - Subtraction 
 
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
 
Explanation:
Step 1: Define Systems
x - 5y = -40
18x - 5y = 45
Step 2: Rewrite Systems
18x - 5y = 45
- Multiply both sides by -1: -18x + 5y = -45
 
Step 3: Redefine Systems
x - 5y = -40
-18x + 5y = -45
Step 4: Solve for x
Elimination
- Combine equations: -17x = -85
 - Divide -17 on both sides: x = 5
 
Step 5: Solve for y
- Define equation: x - 5y = -40
 - Substitute in x: 5 - 5y = -40
 - Isolate y term: -5y = -45
 - Isolate y: y = 9