dikerahui f(x)= ax+b. Jika f(4) =-3 dan f(-2)=9, maka nilai f(6) adalah

F(x) = ax+b

F(4) = a(4)+b
-3 = 4a+b
F(-2) = a(-2)+b
9 = -2a+b
eliminasi
-2a+b = 9
4a+b = -3
________ -
-6a = 12
a = -2
subtitusi
4a+b = -3
4(-2)+b = -3
-8+b = -3
b = 5

F(x) = ax+b
F(x) = -2x+5
F(6) = -2(6)+5
F(6) = -12+5
F(6) = -7