Commenter jdoe said it right: solve for y and leave the rest on the other side.
-x + 3y = 6
3y = 6 + x add x on both sides
3y = x + 6 rearrange to get the x first
y = (x + 6) /3 divide both sides by 3
y = x/3 + 6/3 split the numerator (caution - never split denominators)
y = x/3 + 2 simplify 6/3
Thus the line in slope intercept form of y = mx + b is y = 
The answer is D !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
If two angles are complementary, the sum of their measures is 90 degrees. Call one of the angles x. This means that its complement is 90 - x degrees. But the difference in their measures is 12 degrees.
☁️ Answer ☁️
I got: 7y - 3
Hope it helps.
Have a nice day hyung!~  ̄▽ ̄❤️