24 Blue marbles.
Explanation:
56 - 8 = 48
48 / 2 = 24
so if there are 24 blue marbles, 24 x 2 = 48, and then 8 more is 56.
Answer:
40
Step-by-step explanation:
b + r = 56 (1)
b = 2r + 8 (2)
(1) r = 56 - b
(2) b = 2(56 - b) + 8
b = 112 - 2b + 8
3b = 120
b = 120÷3
b = 40
