Answer:
C
Step-by-step explanation:
The easiest way is to try and proceed. Let's try solving these two.
Start by dividing the top equation by 3
15x/5 - 3y/3 = - 12/3
3x - y = -4
Add 4 to both sides
3x - y + 4 = -4 + 4
3x - y + 4 = 0 Add y to both sides
3x + 4 = y
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Substitute the right side of the second equation into the 4x + 4 = y equation
3x + 4 = 5x + 7
3x - 3x + 4 = 5x - 3x + 7
4 = 2x + 7
subtract 7 from both sides
-3 = 2x
Divide by 2
-1.5 = x
y = 5x + 7
y = 5(-1.5) + 7
y = -7.5
y = -0.5
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By inspection, you can see that the slopes of the lines are not the same.
You can also see that the slope of the first line is not the negative reciprocal of the slope of the second line.
You can also see that the lines intersect at one point (-1.5,-0.5) so they are not the same line.
Answer C
