Answer:
Q3. x = 3, y = -4
Q4. x = 2, y = -3
Q5. x = -1, y = 2
Explanation:
Since the question is asking us to solve the system using elimination/adding, that's what I'll do.
To solve by adding, we add the like terms of both equations together.
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1st question:
x + y = -1
x - y = 7
We add the first term together.
x + x = 2x
Then the second term.
y + -y = y - y = 0
Then the last term.
-1 + 7 = 6
Which becomes:
2x = 6
Then we solve the linear equation.
2x = 6
÷ 2 ÷ 2
x = 3
From the x value, we can then find y.
We can use either equation. In this example, I'll choose the first one.
x + y = -1
Substitute x = 3
3 + y = -1
-3 -3
y = -4
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2nd question:
2x + 2y = -2
3x - 2y = 12
We add the first term together.
2x + 3x = 5x
Then the second term.
2y + - 2y = 2y - 2y = 0
Then the last term.
-2 + 12 = 10
Which becomes:
5x = 10
Then we solve the linear equation.
5x = 10
÷5 ÷5
x = 2
From the x value, we can then find y.
We can use either equation. In this example, I'll choose the first one.
2x + 2y = -2
Substitute x = 2
4 + 2y = -2
-4 -4
2y = -6
÷2 ÷2
y = -3
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3rd question:
6x + 5y = 4
-6x + 7y = 20
We add the first term together.
6x + -6x = 6x - 6x = 0
Then the second term.
5y + 7y = 12y
Then the last term.
4 + 20 = 24
Which becomes:
12y = 24
Then we solve the linear equation.
12y = 24
÷12 ÷12
y = 2
From the x value, we can then find y.
We can use either equation. In this example, I'll choose the first one.
6x + 5y = 4
Substitute y = 2
6x + 10 = 4
-10 -10
6x = -6
÷6 ÷6
x = -1