Dik : f(x)=ax+b, f(1)=9, f-¹(11)=2. Tentukan rumus f(x) dn f-¹(x) please bantu:(

f(x) = ax + b
f(1) = a+b
a+b = 9
b= 9-a
[tex] {f}^{ - 1} (11)= 2[/tex]
mis y = ax +b
[tex]x = \frac{y - b}{a} [/tex]
[tex] {f}^{ - 1} (11) = \frac{11 - b}{a} = 2[/tex]
[tex] \frac{11 - (9 - a)}{a} = 2 \\ 2a = a + 11 - 9 \\ a = 2[/tex]
b =9-2
b = 7
f(x) = 2x + 7
[tex] {f}^{ - 1} (x) = \frac{x - 7}{2} [/tex]

f1=a(1)+b=9
f-1=a(11)+b=2

1a+b=9. |×11| 11a+11b=99
11a+b=2 |×1 |11a+b=2
10b=97
b=9,7

1a+9,7=9
1a=9÷9,7
1a=0,92
a=0,92
Rumus 0,92a+9,7b