I believe the anwser to be 15 marbles
Step-by-step explanation:
3y + x = 12
When y = 3, we have 3(3) + x = 12.
=> 9 + x = 12, x = 3.
OK.......
Evaluating [(21 + 6) - 32] 2 * 9

Your answer would be
-90
H0P3 It H3LPS :)
Answer:
basicly you divided muiltiply and subtract bring back down then bring it on back