Answer: (2, -3)
Concept:
There are in general three ways to solve systems of equations
- Elimination: subtract or add equations together to cancel out variables
- Substitution: Isolating one variable and substitute it with the other equation
- Graphing: plot the equations and determine the intersecting point
Since the question has requirements, we are going to use elimination for this question.
Solve:
Given equation
x + y = -1
2x - y = 7
Multiply 2 on both sides for the equation
2 (x + y) = 2 (-1)
2x - y = 7
2x + 2y = -2
2x - y = 7
Subtract the second equation from the first to eliminate the [x] variable
(2x + 2y) - (2x - y) = (-2) - (7)
3y = -9
Divide 3 on both sides
3y / 3 = -9 / 3
Find the x values by substituting values into one of the equations
x + y = -1
x + (-3) = -1
x - 3 + 3 = - 1 + 3
Hope this helps!! :)
Please let me know if you have any questions