How do you solve for y in ##x-2y=1 ##?

##color(green)(y =( x- 1)/2 ##

##x-color(blue)(2y)=1##

Since we need to solve for ##y## we need to isolate the term containing ##y##:

##x- 1 = color(blue)(2y)##

##color(green)(2)y = x- 1 ##

##y = (x- 1)/color(green)(2) ##

##y =( x- 1)/2 ##