What single step would eliminate the x variable in the system of equations?
x − 2y = 7
3x − y = 15

Question

What single step would eliminate the x variable in the system of equations?    
x − 2y = 7    
3x − y = 15

mertsj · Answer

There is no single step that would do that.

anonymous · Answer

Multiply the top equation by 3 and subtract 3x-y = 15 from 3(x-2y = 7) so it would be 

3x - 6y = 21
- (3x - y = 15)

which should get you -5y = 6

mertsj · Answer

@asdfvg That is not a "single step".

anonymous · Answer

Then there isn't any other way haha

anonymous · Answer

a. Multiply the first equation by −3
b. Multiply the second equation by 7	
c. Multiply the first equation by 2	
d. Multiply the second equation by 5

Here are the options

anonymous · Answer

A

doc.brown · Answer

multiply the first row by -3 and add it to the second row

anonymous · Answer

didn't know there were options but none of those choices are technically in one step...you are multiplying by something and then you are adding it to the second equation to eliminate the x

mertsj · Answer

A

doc.brown · Answer

3x-3x-2y+5y=15-21

doc.brown · Answer

or more precisely,
add -3 times the first row to the second