Question

Diketahui fungsi f(x) = mx + n. Bila f(5) = -32 dan f(12) = -18, maka f(-2) adalah

Answer 1

F (x) = mx + n

f (5) = -32
m(5) + n = -32
5m + n = -32

f (12) = -18
m(12) + n = -18
12m + n = -18

gunakan eliminasi

12m + n = -18
5m + n = -32    -
7m = 14
m = 14/7
m = 2

5m + n = -32
5(2) + n = -32
10 + n = -32
n = -32 - 10
n - 42

f (x) = mx + n
f (x) = 2x - 42

f(-2) = 2(-2) - 42
= -4 - 42
= -46