Simple....
you have 7(5x+3)+3(12-x)....
just take them apart....
7(5x+3)
distribute the 7...
7*5x=35x
and
7*3=21
Now, the other part...
3(12-x)
Distribute the 3...
3*12=36
and
3*-x=-3x
Now, add what you have found....
35x+21+36-3x
32x+57
Thus, your answer, A.
