Respuesta :
Answer:
Step-by-step explanation:
2y = -x +9
3x - 6y = -15
The solution is the value of x and y that will make the two equations true in the same time.
3x-6y = -15; divide both sides by 3
x-2y = -5; substitute 2y for -x+9 because the first equation tell us they are equal
x-(-x+9) = -5; open parenthesis
x+x-9 = -5 ; add 9 to both sides and combine like terms
2x = -5 +9; 2x = 4; divide both sides by 2
x= 2
Substitute x for 2
2y = -x+9 ; 2y = -2 +9 ; 2y = 7; y = 7/2 = 3.5
Solution is (2, 3.5)
Answer:
(2, 7/2)
General Formulas and Concepts:
Pre-Algebra
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
- Left to Right
Equality Properties
- Multiplication Property of Equality
- Division Property of Equality
- Addition Property of Equality
- Subtract Property of Equality
Algebra I
- Coordinates (x, y)
- Terms/Coefficients
- Solving systems of equations using substitution/elimination
Step-by-step explanation:
Step 1: Define Systems
2y = -x + 9
3x - 6y = -15
Step 2: Rewrite Systems
2y = -x + 9
- [Division Property of Equality] Divide 2 on both sides: y = -x/2 + 9/2
Step 3: Redefine Systems
y = -x/2 + 9/2
3x - 6y = -15
Step 4: Solve for x
- Substitute in y: 3x - 6(-x/2 + 9/2) = -15
- Distribute -6: 3x + 3x - 27 = -15
- Combine like terms: 6x - 27 = -15
- [Addition Property of Equality] Add 27 on both sides: 6x = 12
- [Division Property of Equality] Divide 6 on both sides: x = 2
Step 5: Solve for y
- Define original equation: 2y = -x + 9
- Substitute in x: 2y = -2 + 9
- Add: 2y = 7
- [Division Property of Equality] Divide 2 on both sides: y = 7/2