Question

Answer 1

a: (x-2)(x+5)<0

TH1: \(\begin{cases}x-2>0\\ x+5<0\end{cases}\Rightarrow\begin{cases}x>2\\ x<-5\end{cases}\)

=>x∈∅

TH2: \(\begin{cases}x-2<0\\ x+5>0\end{cases}\Rightarrow\begin{cases}x<2\\ x>-5\end{cases}\)

=>-5<x<2

b: \(\left(\frac73-x\right)\left(x-2\right)>0\)

=>\(\left(x-\frac73\right)\left(x-2\right)<0\)

=>\(2