fungsi f(x)= ax + b, jika f(2)= -2 dan f(-3)= 13 maka nilai f(4) adalah

13 = -3x + b
-2 = 2x + b
(dikurang)
15 = -5x
-3 = x

-2 = 2×-3 + b
-2 = -6 + b
4 = b

f(4) = -3(4) + 4
= -12 + 4
= 8

[tex]2a + b = - 2 \\ - 3a + b = 13 \\ dikurang \\ 5a = - 15 \\ a = - 3 \\ b = - 2a - 2 \\ b = - 2( - 3) - 2 \\ b = 6 - 2 \\ b = 4 \\ f(x) = - 3x + 4 \\ = - 3(4) + 4 \\ = - 12 + 4 \\ = - 8[/tex]