Answer:
r = 2
Step-by-step explanation:
I'm assuming we're finding r
11 = 1 + 3r + 2r
Add up the numbers with r
11 = 1 + 5r
Subtract both sides by 1
11 = 1 + 5r
-1 -1
10 = 5r
Divide both sides by the coefficient, 5, to isolate the variable, r
10/5 = 5r/5
r = 2