In this question it basically wants you to leave Y alone in a side of the equation.
In this case,
For 3y=c
For Ay=w
For Y/c=w
Y=cw
For y/a=2c
y=2ac
For a=y+p
y=a-p
For C=y-k
y=C+k
In this case,
For 3y=c
For Ay=w
For Y/c=w
Y=cw
For y/a=2c
y=2ac
For a=y+p
y=a-p
For C=y-k
y=C+k