Sam has twice as many books as Jim. If Sam gives 12 books to Jim, they will have the same number of books. How many books to they have altogether?

3 answers

S = 2J

S - 12 = J + 12

Substitute 2J for S in the second equation and solve for J. Insert that value into the first equation to solve for S. Check by putting both values into the second equation. Add the two.
21
21 savage