Question

Dada a função f: IR -> IR definida por
f (x) = -2x+5 , calcule :
a) f(5)
b) f(2)-f(7)
c) f(1)+f(4)/f(3)
d) x tal que f (x)= 14

Answer 1

a) f(5) = -2x + 5
    f(5) = -2.5 + 5 = -10 + 5 = -5

b)f(2)-f(7)
   -2.7 + 5 - (-2.7 + 5)
   -14 + 5 + 14 + 5= 10
c)f(1) + f(4)/f(3)
-2.1 + 5 + (-2.4 + 5 / -2.3 + 5)
+3 + (-3/-3)
+3 + 1 = 4
d) f(x) = -2x+5
-2x+5 = 14
-2x = 9
x = 9/2