ta có :
+) \(4\frac{5}{9}:2\frac{5}{18}-7=\frac{41}{9}.\frac{18}{41}-7=2-7=-5\)
+) ( 31515\frac{1}{5} : 3,2 + 4,5 . 131453145\frac{31}{45} ) : ( -211212\frac{1}{2} ) = \(\left(\frac{16}{5}.\frac{10}{32}+\frac{45}{10}.\frac{76}{45}\right):\left(\frac{-43}{2}\right)=\left(1+\frac{38}{5}\right).\left(\frac{-2}{43}\right)=\frac{43}{5}.\frac{-2}{43}\) = \(\frac{-2}{5}\)
=> -5 < x< \(\frac{-2}{5}\)
ycbt <=> x = { -1;-2; -3 ;-4 } ... vậy ..