Question

Me ajudem por favor!!

Answer 1

Resposta:

Explicação passo-a-passo:

$a)\ Seja\ y = ax +b=f(x)\ a\ eq.\ da\ reta.\\\\\left \{ {{1=a*1+b} \atop {-3=a*0+b}} \right. \Rightarrow \left \{ {{a=4} \atop {b=-3}} \right. \Rightarrow y=4x-3\\\\b)\ f(-1) = 4*(-1)-3=-7\\\\c)\ f(x) =0 \Rightarrow 4x-3 = 0 \Rightarrow x=\frac{3}{4}\\\\d)\ x\geq \frac{3}{4} \Rightarrow f(x) \geq 0.\ Se\ x < \frac{3}{4} \Rightarrow f(x) <0$