1) first eliminate constant(number without variable) you eliminate constant by doing the inverse operation(if constant is being added, then subtract)(if constant is being subtracted, then add it)
ex: if x+9=32
subtract 9 from both sides to get rid of it
x=23
2) if there is another constant but this constant is being multiplied/divided then do the opposite operation to remove it
$8.25 The first 5 checks are free so you can subtract the 5 from 18 which is 13. Then you multiply 13 & .25 which is equal to $3.25 and then you just add the $5