Tính nhanh ( Nếu có thể )
a ) \(\frac{13}{15}+\frac{4}{7}-\frac{101}{105}\)
b ) \(\frac{2}{5}+\frac{3}{5}\cdot\frac{4}{5}\)
c ) \(\frac{254\cdot399-145}{254+399\cdot253}\)
d ) \(\frac{5932+6001\cdot5931}{5932\cdot6001-69}\)
e ) \(\frac{1}{5}:\frac{2}{7}\)
GẤP , CỰC KÌ GẤP ..... BẠN NÀO TRÌNH BÀY ĐẦY ĐỦ MÌNH TICK .... T_T
a )\(\frac{13}{15}+\frac{4}{7}-\frac{101}{105}\)
\(=\frac{91}{105}+\frac{60}{105}-\frac{101}{105}\)
\(=\frac{50}{105}\)
\(=\frac{10}{21}\)
b ) \(\frac{2}{5}+\frac{3}{5}\cdot\frac{4}{5}\)
\(=\frac{2}{5}+\frac{12}{25}\)
\(=\frac{10}{25}+\frac{12}{25}\)
\(=\frac{22}{25}\)
c )\(\frac{254\cdot399-145}{254+399\cdot253}\)
\(=\frac{253\cdot399+399-145}{254+399\cdot253}\)
\(=\frac{253\cdot399+254}{254+399\cdot253}\)
\(=1\)
d )\(\frac{5932+6001\cdot5931}{5932\cdot6001-69}\)
\(=\frac{5932+6001\cdot5931}{5931\cdot6001+6001-69}\)
\(=\frac{5932+6001\cdot5931}{5931\cdot6001+5932}\)
\(=1\)
e )\(\frac{1}{5}\div\frac{2}{7}\)
\(=\frac{1}{5}\cdot\frac{7}{2}\)
\(=\frac{7}{10}\)
hok tốt nha
