Bài 1:Tính
1)\(\frac{7}{5}+\frac{-8}{5}\) ; 2)\(\frac{-6}{5}\times\frac{15}{24}\) ; 3) \(\left(\frac{2}{3}+1,5\right)-3,5:7\frac{1}{2}\) ; 4)\(\frac{5}{8}-\frac{-7}{9}\) ; 5)\(\frac{-7}{3}\times\frac{12}{28}\).
Bài 2:Tìm x
1)\(x-70=-45\) ; 2)\(\frac{4}{7}:x=\frac{12}{28}\) ; 3)\(\left(\frac{2}{3}x+1,5\right)-3,5:7\frac{1}{2}\) ;
4)x-50=-35 ;5)\(\frac{4}{7}\times x=\frac{11}{28}\) ;6)\(\left(\frac{2}{3}x+2,5\right):2\frac{2}{6}=6\)
m.n ơi!!!
giúp em vs ạ,e đag cần gấp,e sắp thi r
m.n có trước cho e ngày 28/4/2019 nhé :)
Bài 2 :
1) \(x-70=-45\) 2) \(\frac{4}{7}:x=\frac{12}{28}\)
\(\Rightarrow\) \(x=-45+70\) \(\Rightarrow x=\frac{4}{7}:\frac{12}{28}\)
\(\Rightarrow\) \(x=25\) \(\Rightarrow x=\frac{4}{3}\)
Vậy \(x=25\) Vậy \(x=\frac{4}{3}\)
3) Giống câu c) ở bài 1
4) \(x-50=-35\) 5) \(\frac{4}{7}.x=\frac{11}{18}\)
\(\Rightarrow x=-35+50\) \(\Rightarrow x=\frac{11}{28}:\frac{4}{7}\)
\(\Rightarrow x=15\) \(\Rightarrow x=\frac{77}{72}\)
Vậy \(x=15\) Vậy \(x=\frac{77}{72}\)
6) \(\left(\frac{2}{3}x+2,5\right):2\frac{2}{6}=6\)
\(\Rightarrow\)\(\left(\frac{2}{3}x+2,5\right):\frac{14}{6}=6\)
\(\Rightarrow\) \(\frac{2}{3}x+2,5=6.\frac{14}{6}\)
\(\Rightarrow\frac{2}{3}x+2,5=14\)
\(\Rightarrow\frac{2}{3}x=\frac{23}{2}\)
\(\Rightarrow x=\frac{23}{2}:\frac{2}{3}\)
\(\Rightarrow x=\frac{69}{4}\)
Vậy \(x=\frac{69}{4}\)
Bài 1:
1) \(\frac{7}{5}+\frac{-8}{5}=-\frac{1}{5}\)
2) \(-\frac{6}{5}.\frac{15}{24}=-\frac{3}{4}\)
3) \(\left(\frac{2}{3}+1,5\right)-3,5:7\frac{1}{2}=\)\(\frac{13}{6}-\frac{7}{15}=\frac{17}{10}\)
4) \(\frac{5}{8}-\frac{-7}{9}=\frac{5}{8}+\frac{7}{9}=\frac{101}{72}\)
5)\(\frac{-7}{3}.\frac{12}{28}=-1\)
