Question

Suatu fungsi f(x) = -4×+7
tentukan =
a. f(-5)
b. jika f(a) = 17 tentukan nilai a !

Answer 1

F(x) = - 4x + 7

Yang A
f(x) = - 4x + 7
f(- 5) = - 4(- 5) + 7
         = 20 + 7
         = 27

Yang B
f(x) = - 4x + 7
f(a) = 17

f(x) = - 4x + 7
17 = - 4x + 7
4x = 7 - 17
4x = - 10
  x = - 10/4
  x = - 5/2

Answer 2

F(x) = -4x + 7
a. f(-5) = -4 (-5) + 7
= 20 + 7
= 2
b. f(a) = 17
f(a)=> -4a+ 7 = 17
-4a = 10
a = 10/-4
a = - 5/2