Diketahui fungsi linear R:x > ax+b memetakan 5>5, memetakan 8>7, dan memetakan p>19 . nilai p adalah

f(x) = ax + b
f(5) = 5a + b = 5
f(8) = 8a + b = 7
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........ -3a = -2 => a = 2/3
5a + b = 5
5(2/3) + b = 5
b = 5 - 10/3 = 5/3

f(x) = 2/3 x + 5/3
f(p) = 2/3 p + 5/3 = 19 .......... kali 3
=> 2p + 5 = 57
=> 2p = 52
=> p = 26