Answer: y = -1 and x = 3
Explanation:
x=-2y+6
3x-4y = 28
There are two ways to solve this: 1) solve directly with the equations, and 2) graph the line and look for the intersection.
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Use the definition of x from the first equation and substitute it in the second:
3x-4y = 28
3(-2y+6)-4y = 28
-6y + 18 -4y = 28
-10y = 10
y = - 1
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Graph the two lines and find the value of y at the point they intersect. See the attachment.
y = -1 at x= 8
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For the second question:
y=3x-10
4x+5y=7
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4x+5y=7
4x+5(3x-10)=7
4x+15x-50=7
19x = 57
x = 3
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