Question

escreva a função afim f (x)=ax+b tal que f (-1)=7 e f (2)=1

Answer 1

f(x)=ax+b
f(-1)=a.(-1)+b
f(-1)=-a+b
f(-1)=7
-a+b=7

f(2)=a.2+b
f(2)=2a+b
f(2)=1
2a+b=1

$\left \{ {{-a+b=7} \atop {2a+b=1}} \right.$

b=7+a
2a+7+a=1
3a+7=1
3a=1-7
3a=-6
a=-6/3
a=-2
b=7+(-2)
b=7-2
b=5