3x + 2 - 3( 2x - 1 ) <---- distribute the -3 [don't forget the -negative sign]
3x + 2 -6x + 3 <----- now combine the like terms[:terms with the same variables]
[to add 3x and -6x just add 3 and -6 which is -3 and just copy the variable]
[add 2 and 3 and this gives you 5]
-3x + 5 <---- this is your final answer