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Answer: 
Explanation:
so basically f(g(x)) is telling you to plug the entire g(x) equation into x in the f(x) equation so it will look like this
2(
) + 1
and then simplify


At first situation, ratio = x/y = 1/5
5x = y -------Equation (i)
Now, after adding 5 more red, it is = x + 5 / y+5 = 1/3
y+5 = 3(x + 5)
y + 5 = 3x + 15
y - 3x = 15 - 5
Substitute the value of y from equation (1),
5x - 3x = 15 - 5
2x = 10
x = 10/2
x = 5
Originally, There were 5 red marbles in the bag
Hope this helps!