The number of problems Shelly has to complete is 25 problems
x = 10 + 2/7x
x - 2/7x = 10
(7x-2x)/7 = 10
5/7x = 10
x = 10 ÷ 5/7
= 10 × 7/5
= 70/5
x = 35 problems
So,
Number of problems to complete = Total problems - completed problem
= 35 - 10
= 25 problems
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