Fungsi ( pake cara Eliminasi dan Substitusi ) f(x) = ax + b f(-4) = 8 f(3) = -13 2a - 3b = ???? Thankyouuu !!!!

f(x) = ax + b
f(-4) = a.-4 + b
8 = -4a + b ••• (1)

f(3) = a.3 + b
-13 = 3a + b ••• (2)

Eliminasi
-4a + b = 8
3a + b = -13
---------------- -
-7a = -21
a = 3

Substitusi
-4a + b = 8
-4.3 + b = 8
-12 + b = 8
b = 20

Maka,
2a - 3b
= 2 (3) - 3 (20)
= 6 - 60
= -54