diketahui f(x)=ax+b jika f(-2) =-11 dan f(3)=14 tentukan f(-4)=....

Materi : Fungsi Linear

Pembahasan :
f(x) = ax + b
f(-2) = -2a + b = -11
f(3) = 3a + b = 14
—————————— (-)
5a = 25
a = 5

Substitusi...
3a + b = 14
3(5) + b = 14
b = 14 - 15
b = -1

Maka...
f(x) = ax + b
f(x) = 5x - 1

f(-4) = 5(-4) - 1
f(-4) = -20 - 1
f(-4) = -21

f(x)=ax+b
f(-2) = -2a+b
-11= -2a+b
f(3)=3a+b
14=3a+b

-11=-2a+b
14=3a+b
-------------- —
-25=-5a
5=a

-11=-2a+b
-11=-2.5+b
-11=-10+b
-11+10=b
-1=b

f(x)=ax+b
f(x)=5x-1
f(-4)=5.-4-1 = -20-1 =-21