Two more than a certain number is 15 less than twice the number

The given certain number is 17.

Step-by-step explanation:

Let the given certain number = k

So, according to the question,

2 + k = 2k - 15

or, 2 + 15 = 2k - k

or, k = 17

hence the given certain number is 17.

CHECK:

2 more than 17 = 19, and

19 is 15 less than 2 times 17