Get x by itself. Start furthest away from x. We will first subtract 1 on both sides of the equation.
y - 1 = 1/4 x
Now we need to get rid of the 1/4. Another way to write 1/4 x is simply x/4, meaning x is being divided by 4. We need to do the opposite and multiply both sides by 4.
4(y-1) = x
You can leave it like that or distribute the 4.
x = 4y - 4