If the solution of (2x-r / 3) - (x-3r / 2) = 1 is x = - 1, then the value of R is

If the solution of (2x-r / 3) - (x-3r / 2) = 1 is x = - 1, then the value of R is

Substituting x = - 1 into the linear equation (2x-r / 3) - (x-3r / 2) = 1, we get
(-2-R/3)-(-2-3R/2)=1
To get rid of the brackets, you have to
-2-R/3+2+3R/2=1
7R/6=1
R=6/7