Respuesta :
12-3b<9 (subtract 12 from both sides)
-3b<-3 (divide by -3, but since you're dividing by a negative the sign flips)
b>1
If your getting b isolated you would start by subtracting 12 from both sides12 - 3b < 9 -----------------> -3b < -3-12 -12
Then, divide negative 3 from both sides (note: Dividing and multiplying negatives switches the direction of the < or > sign.
-3b < -3 ------------------> b > 1
/-3 /-3
Then, divide negative 3 from both sides (note: Dividing and multiplying negatives switches the direction of the < or > sign.
-3b < -3 ------------------> b > 1
/-3 /-3