Question

[huyen dao]

111/37<x<91/13

-84/14<x<108/9

-x/4=-9/x

Answer 1

[Thúy Vy]

1)111/37<x<91/13

\(\Leftrightarrow\)\(\frac{1443}{481}\)<x<\(\frac{3367}{481}\)

vậy x\(\in\)\(\left\{\frac{1444}{481};......;\frac{3366}{481}\right\}\)

2)-84/14<x<108/9

\(\Leftrightarrow\)\(\frac{-801}{126}\)<x<\(\frac{432}{126}\)

vậy x\(\in\)\(\left\{\frac{-800}{126};.......;\frac{431}{126}\right\}\)

3)\(\frac{-x}{4}\)=\(\frac{-9}{x}\)\(\Rightarrow\)-x.x=(-x)²=4.(-9)=-36

\(\Rightarrow\)(-x)²=-36=(-6)²

vậy -x=6;x=6