Let the number of marbles that Kamal had in the beginning= K
Then Jason had (128 - K)
Let the number of marbles that Jason gave away = G
Then the number of marbles that Kamal gave away = 3G
And the number that Kamal had left = K - 3G
And we know that, from Jason's point of view
What he started with - what he gave away = what he had left
(128 - K) - G = G - 4 simplify
(128 - K) = 2G - 4
128 + 4 - 2G = K
132 - 2G = K (1)
And from Kamal's point of view we have that
3 times what he had left = what Jason had left
3(K - 3G) = G - 4 (2)
Sub (1) into (2)
3 ( 132 - 2G - 3G) = G - 4
396 - 15G = G - 4
400 = 16G
G = 400/16 = 25
What Jason started with = 2G - 4 = 2*25 - 4 = 46