Question

Fungsi f dinyatakan dengan rumus f(x) = ax + b. jika f(2) = 3 dan f(-3) = 13, nilai dari -a + b adalah

Answer 1

F(2) = 2a + b
3 = 2a + b
f (-3) = -3a + b
13 = -3a +b 
lalu dieliminasi akan didapatkan
5a = -10
a = -2
b= -5
-a + b = -(-2) + (-5) = -3

Answer 2

F(x) = ax + b
f(2) = 2a + b = 3
f(-3) = -3a + b = 13
f(2) - f(-3) : 5a = -10
a = -10÷5
a = -2
2a + b = 3
2.-2 + b = 3
-4 + b = 3
b = 3 + 4
b = 7

-a + b = -(-2) + 7
-a + b = 2 + 7
-a + b = 9