Y+ 8.3 = 12.7 show me how to got the answer

Could somebody me with this radical simplification?

If f(x)=x/2-3 and g(x)=4x^2+x-4, find (f+g)(x)

Jane evaluates x^2-3x+5 for x=2 below. step 1: (-2)^2-()+5 step 2: =-4+6+5 step 3: =7 what, if any, was jane’s mistake? a)jane made no mistakes. b)jane incorrectly evaluated(-2)^2 in step 2. c)jane incorrectly added the terms in step 3. d)jane incorrectly substituted in x=-2in step 1.