Question

Suatu fungsi dirumuskan dengan f(x) = ax + b. Jikaf(-2) = 10 dan f(3) = -5 nilai f(5) adalah

Answer 1

F(x) = ax + b
f(-2) = a(-2) + b
= -2a + b = 10

f(3) = 3a + b = -5

-2a + b = 10
3a + b = -5
__________ -
-5a = 15
a = 15/-5 = -3

-2a + b = 10
-2 (-3) + b = 10
6 + b = 10
b = 10-6 = 4

f(5) = (-3)(5) + 4
= -15 + 4 = -11