The running time for movie A is 33 mins more than twice the running time for movie B. If the running time for movie A is subtracted from triple the running time for movie B, the result is 57 mins. find the running time for each movie..
Movie A-
Movie B-

use what they tell you to create the equations  a=33+2b  & 57=3b-afor this to work we need to substitute a variable to get rid of it. look at           57=3b-a (lets switch it around s that the equation reads "a=")          57+a=3b          a=3b-57 (this is our new equations)so now we know that a=33+2b & a=3b-57so we can write 33+2b=3b-57. we have now "gotten rid" of "a"SOLVE FOR B 33+2b=3b-57  (get variable alone)33= 3b-2b-57  (subtract and add accordingly)33= b-5733+57=b90=b     (this means that movie b is 90 long)SOLVE FOR Ayou can plug "b" into any of the original equations.a=33+2b a=33+2(90)a=33+180a=213CHECKplug "a" into any of the original equations to find "b" if b=90 then you know you've done it right 213=33+2b213-33=2b180=2b180/2=b90=bhope this helps :)

X is the running time for movie A and y the running time for movie BX = 2y + 333y - × = 57x- 2y = 33-× + 3y = 57  => y = 90=> x 33 + 180 = 213