let f [x]= 2x-7 if f [a]= 11 find f [5] + f [2]

f(a) = 2a - 7 = 11
             2a = 11 + 7
               a = 18/2
               a = 9

f(5) = 2.5 - 7 = 10 - 7 = 3
f(2) = 2.2 - 7 = 4 - 7 = -3
f(5) + f(2) = 3 + -3 = 0