Respuesta :
answer: b= 15
step by step:
plug the 12 into the x position to make it 12+4b=72
subtract on both sides to get
4b=60
divide and b=15!
step by step:
plug the 12 into the x position to make it 12+4b=72
subtract on both sides to get
4b=60
divide and b=15!
If x=12, then you subtract 12 from 72 and get 60. Then you divide 60 /4 and get 15.