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put this solution on YOUR website!Let x stand for the number of years from now. So if this year ring 1 is 18, in x years it will be 18+x and the second ring will be 46+x.
The question asks when will the second ring be twice as old. Twice indicates we're multiplying by two. So in essence, the question asks how many years will have passes until twice (2 times) the age of the younger ring (18+x) equals (=)the age of the second (46+x) or:

Distribute on the right:

Subtract x and 36 from both sides.

So in ten years ring 1 will be 18+10=28 and the second ring will be 46+10=56. 28 doubled is 56, check.