Question

Determine a função afim f(x) = ax + b, sabendo que f(1) = 3 e f(–3) = –6.​

Answer 1

f(1) = ax + b = 3 => a + b = 3
f(-3) = ax + b = -6 => -3a + b = -6

a + b = 3 => b = 3 - a
-3a + b = -6

-3a + (3 - a) = -6
-3a + 3 - a = -6
-3a - a = -6-3 => -4a = -9 .(-1) = a = 9/4

b = 3 - 9/4 => b = 3/4 ( resolvi o MMC)

Função é: f(x) = 9/4x + 3/4