have to take a test with equations like this... 12x+4y=-1 followed by y=-3x+1 can anyone help me solve this so i can do other problems similar to it?

Question

have to take a test with equations like this... 12x+4y=-1  followed by  y=-3x+1 can anyone help me solve this so i can do other problems similar to it?

anonymous · Answer

What are you solving for? If you are solving for x and y, then you can't for this system of equations because they are parallel lines/have the same slope.

anonymous · Answer

yes I am solving for x and y. Thank you for your help. I didnt know they were parallel. I need to learn how to find x and y in a problem like this for my test!!

anonymous · Answer

An example problem would be 
12x+4y=0
y=2x-10
substitute y from the second equation into the first equation
12x+4(2x-10)=0
solve for x
12x+8x-40=0
20x-40=0
20x=40
x=2 
plug it back into the second equation
y=2(2)-10
y=4-10=-6
anwer is (2,-6)

anonymous · Answer

Thank you so much!

precal · Answer

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