Answer:
12 marbles per bag
Explanation:
Your equation would be 3x=x+24 because you have 3 bags of marbles with x number of marbles per bag, and your friend has 1 bag with x marbles plus 2 additional marbles
Then you solve this equation
3x=x+24
Subtract x from both sides
2x=24
divide both sides by 2
x=12