Not "solve," but "evaluate."
What's f(-5)? You must decide which half of the given function to use and then plug in -5 for x: -5 is equal to or smaller than -1, so use f1(x) = 2x^2 - 1.
Then f1(-5) = 2(-5)^2 - 1 = 49 (answer)
You must use f1(x) to evaluate f(-1), and f2(x) to evaluate f(5).