Question

Diketahui f(x) =ax+b ,f (2) =10 ,dan f(3)=5
A. Tentukan rumus fungsi
B. F(-4)+f(10)

Answer 1

A. f(2) = 10
2a + b = 10

f(3) = 5
3a + b = 5

3a + b = 5
2a + b = 10 -
-------------------
a = -5

2a + b = 10
2 × (-5) + b = 10
-10 + b = 10
b = 10 + 10
b = 20

f(x) = -5x + 20

b. f(-4) + f(10)
= (-5 × (-4) + 20) + (-5 × 10 + 20)
= (20 + 20) + (-50 + 20)
= 40 + (-30)
= 40 - 30
= 10