so, okay. You take (3x+18) and multiply the whole thing by .100 to turn it into a percent. so you take .100(3x+18) use the distributive property. in order to convert just move the decimal place behind the 3 over the amount of zeros in 100 to the right because we are multiplying by a decimal. like so.
3.
.003
there you go, perfect!
now do the same with 18
18.
.018
There we have it!
now dont forget about x, you simply put it back behind the .003
3% of x Plus 18%
there weee gooo