Question

F(x)=ax+b dgn f(1)=3 dan f(-3)=11 maka tentukan nilai a dan b

Answer 1

F(x)=ax+b
f(1)=3 -> f(1)=a(1)+b=3 -> a+b=3 (persamaan 1)
f(-3)=11 -> f(-3)=a(-3)+b=11 -> -3+b=11 (persamaan 2)
Nah sekarang pakai cara eliminasi.
a+b=3
-3a+b=11
--------- (-) dikurang
4a = -8
a = -2
Masukkan kesalah satu persamaan :
a+b=3
(-2)+b=3
b=5

Answer 2

F(x) = ax + b

f(1) = a(1) + b = 3
a + b = 3

f(-3) = a(-3) + b = 11
-3a + b = 11

Eliminasi
pers 1 & 2
Diperoleh a = -2

Subs a = -2 ke pers 1
a + b = 3
-2 + b = 3
b = 3+ 2
b = 5