Answer:
r=-8
Step-by-step explanation:
-15 = 2r + 1. we know 2r has to be -16 because -16 + 1 = -15. -16 / 2 = -8
The answer is r=-8
-15 = 2r + 1
-15-1=2r+1-1
-16=2r
-16/2=2r/2
-8=r
