12 blue marbles for 15 white marbles because you multiply 5*3 so multiply 4*3 to get answer
Answer:

Step-by-step explanation:
If
, and 
then
can be calculated via:

Answer:
26
Step-by-step explanation:
Step-by-step explanation:
5(x - 3) = 3 + 5x + 3x
5x - 15 = 3 + 8x
5x - 8x = 3 + 15
-3x = 18
x = 18/-3
x = -6