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The first question:3y=4x+7 (1)
-4x-4y=28 (2)
Let's plug in x = -4, -3, 3, and 4 and see the y-values :)
I have attached the table since it's hard to make a table with text :P
As you can see, when x = -4, that is when the y-values are equal. That means that is the solution to the system of equations. Your answer is
A) (-4, -3).
The second question:</span><span>-3x-y=-10 (1)
4x-4y=8 (2)
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When you graph both equations, you will see that they intersect at
D) (3, 1).
The third question:
We need to find the lines for revenues and expenses.
To find the line for revenues, make months the x-value and revenues the y-values. And find the equation. You should get y = 4,100x + 300.
To find the line for expenses, make months the x-value and expenses the y-values. And find the equation. You should get y = 1,900x + 19,990.
Now graph both solutions and see where they intersect. They intersect at approximately (8.95, 36995)
That would be during the month of
C) August.