Question

12 r - 18 = 13 r + 18

Answer 1

First you want to isolate the variable, do this by adding 18 to both sides. You're left with 12r = 13r + 36, then subtract 13r to get the variables alone. You're then left with -1r = 36, multiply by -1 to remove the negative. The final result would be (1) r = 36.

Answer 2

12r-18=13r+18
-12r. -12r
1r-18=18
+18 +18
1r= 36
1r/1=36/1
r=36