Okay, here we have this:
Considering the provided information, we are going to calculate the requested interval, so we obtain the following:
Then we will assume that the unknown number is x:
-26<2x-2<30
-26+2<2x<30+2
-24<2x<32
-24/2-12(-12, 16)
Finally we obtain that the interval solution is (-12, 16).