3x + 1/5y = 7
To solve for a variable, you have to isolate the variable that you want to solve. In this case, we want to solve for "x," so we must isolate "x."
So, subtract 1/5y from both sides.
3x = -1/5y + 7
Then, divide both sides by 3.
3x ÷ 3 = (-1/5y + 7) ÷ 3
Simplify.
x = -1/15y + 7/3
~Hope I helped!~