Answer: No, he is not correct, the correct equation is:
225 + 2*r = 1475
Solving that, we can find that each bag of raisins has 625 grams of raisins.
Explanation:
I suppose that the problem is as follows:
"Sam had 225 grams of raisins. After buying another two bags of raisins he then had 1475 grams of raisins"
Then, if each bag of raisings has r grams of raisings, two bags will have two times that, or:
2*r grams of raisings.
Then if we take what he had at the beginning, and we add these 2*r grams, we should get the 1475 grams that he has at the end:
225 + 2*r = 1475
This is what he should get.
and we can solve it for r, to get:
2*r = 1475 - 225 = 1250
r = 1250/2 = 625
r = 625
This means that each bag of raisins has 625 grams of raisins.
But instead, he got:
225*r + 2 = 1475
In this case, he multiplied his previous amount of raisings by the amount that each bag has, so his equation is wrong.