You are correct to start with x and x+2. 

Let x= smaller odd number

x+2= larger odd number 

Now, translate the sentence from English into math symbols. 

". . . twice the greater is 17 more than the lesser."

2(x+2) = x+17 

2x+4 = x + 17 

Subtract x from each side:

2x-x+4= x-x + 17

x+4 = 17 

Subtract 4 from each side:

x+4-4=17-4

x=13 Smaller

x+2= 15 Larger 

Check: 

twice the greater is 17 more than the lesser.

2*15= 13+17 

It checks!!