Respuesta :
Answer:r=-3
Step-by-step explanation:
multiply the 3(3r+4) that gives you 9r+12 on that side
subtract 4r from the other side and from 9r and you are left with -3=5r+12
subtract 12 from that side and from -3 and you get -15=5r
divide -15 and 5r by 5 (here's how it looks --) -15/5 = 5r/5
you get -3=r