Question

Diketahui rumus fungsi f(×)=m×+n. jika f(4)=25 dan f(-3)=11. tentukan:
a.) nilai m dan n b.) rumus fungsi f(×).
c.) nilai f (7)
tolong dibantu ya gannss... :)

Answer 1

F(x) = mx+n
f(4) = 25
25 = 4m + n
f(-3) = 11
11 = -3m + n

Eliminasi!
4m+n = 25
-3m + n = 11
= 7m = 14
m = 14/7
m = 2

4m + n = 25
4(2) +n =25
8 + n = 25
n = 25 - 8
n = 17

Fungsi f(x) = 2x + 17
f(7) = 2.7 + 17
14 + 17
= 31

Answer 2

F(x) = mx +n
f(4) = 4m+n = 25
f(-3)= -3m + n = 11

(4m + n = 25) - (-3m + n = 11)
---> 7m = 14
        m= 2
jika m= 2
maka n ----> 4x2 + n = 25
                     8  + n = 25
                     n = 25-8
                        = 17
Nilai f(7)  = mx + n
             = 2 x 7 + 17
             = 14+17
             = 31