y=a+b+c6

Rewrite the equation as a+b+c6=y.

a+b+c6=y

Multiply both sides of the equation by 6.

6⋅a+b+c6=6⋅y

Cancel the common factor.

6⋅a+b+c6=6⋅y

Rewrite the expression.

a+b+c=6⋅y

a+b+c=6y

Subtract a from both sides of the equation.

b+c=6y-a

Subtract c from both sides of the equation.

b=6y-a-c

b=6y-a-c

Solve for b y=(a+b+c)/6