Question

Nomor 5 aja.
kalo bisa ikut dengan cara.

Answer 1

F(x) = ax + b

f(4) = 4a + b = 7
f(2) = 2a + b = 1    -
         2a       = 6
           a       = 3

2a + b = 1
2(3) + b = 1
6 + b = 1
b = 1 - 6
b = -5

a + 2b
3 + 2(-5)
3 + -10
3 - 10
-7

Answer 2

F(x) = ax + b

pers 1
f(2) = 2a + b
1 = 2a + b

pers 2
f(4) = 4a + b
7 = 4a + b

eliminasikan pers 2 dg pers 1
7 = 4a + b
1 = 2a + b    -
6 = 2a 
6 : 2 = a
3 = a

cari b
1 = 2a + b
1 = 2 x 3 + b
1 - 6 = 6 - 6 + b
-5 = b

sehingga a = 3, b = -2
maka nilai dari
a + 2b
3 + (2 x -5)
3 + -10
3 - 10
-7 = A