suatu fungsi dirumuskan f(x) =ax-b . Jika bayangandari -5 adalah 14 dan bayangan dari 7 adalah 26 tentukan. a.nilai a dan b b.rumus fungsinya

f(x) = ax-b
f(-5) = 14
f(7) = 26

f(-5) = a(-5)-b
14 = -5a-b............(1)
f(7) = a(7)-b
26 = 7a-b.............(2)

7a-b = 26...............(2)
-5a-b = 14................(1)
_________________ _
12a = 12
a = 1

7a-b = 26..............(2)
7(1)-b = 26
7-b = 26
-b = 26-7
-b = 19
b = -19

f(x) = ax-b
f(x) = (1)x - (-19)
f(x) = x+19