Answer: Sam 25 marbles.
Step-by-step explanation: Given that Sam and Edna have 56 marbles together and Edna has 6 times more marbles than Sam.
We are to find the number of marbles that Sam has.
Let x and y represents the number of marbles that Sam and Edna has respectively.
Then, according to the given information, we have

and

Thus, Sam has 25 marbles.