1. substitute (multiply everything in ( ) by 3 or number to outside)
3 (6-x)= 18-3x
2. simplify left side (can add 3x and 2x because they both have x)
18-3x+2x=15
18-5x=15
3. get 5x alone (subtract 18)
-5x= -3
4. get x alone (divide by -5)
-3/-5= 0.6 (negative times negative = positive)
x=0.6 <---------