solve using the multiplication principle -3a<-15

Question

solve usins addition and multiplication 3c+4<-6
3c+4-4<-6+4
3c<-2
3c/3<2/3
c<-2/3 is this right

Answer 1

No.

Your error is in this line:

3c+4-4<-6+4

You should subtract 4 from both sides.

-6 and -4 = -10