solve by multiply then add

Question

3x - y = 8

Answer 1

I am nearly as confused as you guys (maybe more) but my interpretation is that they want you to make y the subject of the equation by performing those mathematical operations such that:

 

3x - y = 8

 

Multiply both sides of the equation by -1.

-1(3x-y) = -1(8)

-3x + y = -8

 

Then add -3x to both sides of the equation:

-3x + y + 3x = -8 + 3x 

-3x + y + 3x = -8 + 3x

 

 

y = -8 + 3x 

 

Like Mark implied, this question was VERY vaguely phrased so I would re-check the source of the question (textbook or teacher) to see if more information was given.