I'll solve each system of linear equations step by step.
Problem 1:
2x + 3y = -6
-2x + 3y = 6
Adding the two equations:
(2x + 3y) + (-2x + 3y) = -6 + 6
6y = 0
y = 0
Substituting y = 0 into the first equation:
2x + 3(0) = -6
2x = -6
x = -3
Solution: (-3, 0)
Problem 2:
-2x + 3y = -9
x + y = 2
From the second equation: x = 2 - y
Substituting into the first equation:
-2(2 - y) + 3y = -9
-4 + 2y + 3y = -9
5y = -5
y = -1
Then: x = 2 - (-1) = 3
Solution: (3, -1)
Problem 3:
-x + 3y = 6
4x + 3y = -9
Subtracting the first from the second:
(4x + 3y) - (-x + 3y) = -9 - 6
5x = -15
x = -3
Substituting x = -3 into the first equation:
-(-3) + 3y = 6
3 + 3y = 6
3y = 3
y = 1
Solution: (-3, 1)
Problem 4:
-x + 3y = 6
-5x + 3y = 6
Subtracting the first from the second:
(-5x + 3y) - (-x + 3y) = 6 - 6
-4x = 0
x = 0
Substituting x = 0 into the first equation:
-(0) + 3y = 6
3y = 6
y = 2
Solution: (0, 2)
Problem 5:
-5x + 4y = -16
x + 4y = 8
Subtracting the second from the first:
(-5x + 4y) - (x + 4y) = -16 - 8
-6x = -24
x = 4
Substituting x = 4 into the second equation:
4 + 4y = 8
4y = 4
y = 1
Solution: (4, 1)
Problem 6:
2x + y = 2
-x + y = -4
Subtracting the second from the first:
(2x + y) - (-x + y) = 2 - (-4)
3x = 6
x = 2
Substituting x = 2 into the first equation:
2(2) + y = 2
4 + y = 2
y = -2
Solution: (2, -2)
Problem 7:
5x + 3y = 12
-x + 3y = -6
Subtracting the second from the first:
(5x + 3y) - (-x + 3y) = 12 - (-6)
6x = 18
x = 3
Substituting x = 3 into the second equation:
-(3) + 3y = -6
-3 + 3y = -6
3y = -3
y = -1
Solution: (3, -1)
Problem 8:
-x + 2y = -6
3x + 2y = 2
Subtracting the first from the second:
(3x + 2y) - (-x + 2y) = 2 - (-6)
4x = 8
x = 2
Substituting x = 2 into the first equation:
-(2) + 2y = -6
-2 + 2y = -6
2y = -4
y = -2
Solution: (2, -2)
Final Answer:
1) (-3, 0)
2) (3, -1)
3) (-3, 1)
4) (0, 2)
5) (4, 1)
6) (2, -2)
7) (3, -1)
8) (2, -2)
Parent Tip: Review the logic above to help your child master the concept of solve each system by graphing worksheet answers.