Question

Dada a função f: R R definida por f(x)= ax + b , com a e b reais , calcule o valor de a e b sabendo que f(-5)=3 e f(2) = -4

Answer 1

Resposta:

boam dia amiga tudo em?

Answer 2

$f(x)=ax+b\\\\f(-5)=ax+b\\3=a*(-5)+b\\-5a+b=3\\\\f(2)=ax+b\\-4=a*2+b\\2a+b=-4\\\\\displaystyle\left\{ \begin{array}{c} -5a+b=3 \\ 2a+b=-4 \end{array}\right.\\\displaystyle\left\{ \begin{array}{c} -5a+b=3 \\ 2a+b=-4 (-1) \end{array}\right.\\\displaystyle\left\{ \begin{array}{c} -5a+b=3 \\ -2a-b=4 \end{array}\right.\\\\-7a=7\\a=-1\\\\-4=2a+b\\-4=-2+b\\b=-2$

Com isso, a = -1 e b = -2.