Sam had 225 grams of raisins. After buying another two bags of raisins he then had 175 grams of raisins
He writes this equation where r represents number of bags of raisins to describe how
225r+2=1475
Is he correct? Explain your answer.
How many grams of raisins were in one bag?

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.

Step-by-step 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.