Answer:
15) 3(4+r)=-18
3x4+3xr
12+3r= -18
-12 -12
3r= -30
/3 /3
r= -10
Step-by-step explanation:
distribute the 3 to the 4 and the r you should then have 12+3r=-18 and so subtract from both sides 12 and you should have 3r=-30 divide both sides by 3 and you get your answer r=-10
