\(\frac{20}{7}.\frac{13}{8}+\frac{71}{8}.\frac{20}{8}-\frac{13}{8}.\frac{20}{7}\)
\(=\frac{20}{8}.\frac{13}{7}+\frac{71}{8}.\frac{20}{8}-\frac{20}{8}.\frac{13}{7}\)
\(=\frac{20}{8}.\left(\frac{13}{7}+\frac{71}{8}-\frac{13}{7}\right)\)
\(=\frac{20}{8}.\left(0+\frac{71}{8}\right)\)
\(=\frac{20}{8}.\frac{71}{8}\)
\(=\frac{355}{16}\)
Ủng hộ mk nha ^_-
\(\frac{20}{7}\cdot\frac{13}{8}+\frac{71}{8}\cdot\frac{20}{8}-\frac{13}{8}\cdot\frac{20}{7}=\frac{71}{8}\cdot\frac{5}{2}=\frac{355}{16}\)
20/7 x 13/8 + 71/8 x 20/8 - 13/8 x 20/7 =355/16
đúng 100% đó
\(\frac{20}{7}\times\frac{13}{8}+\frac{71}{8}\times\frac{20}{8}-\frac{13}{8}\times\frac{20}{7}\)
\(=\frac{20}{8}\times\frac{13}{7}+\frac{71}{8}\times\frac{20}{8}-\frac{13}{7}\times\frac{20}{8}\)
\(=\frac{20}{8}\times\left(\frac{13}{7}+\frac{71}{8}-\frac{13}{7}\right)\)
\(=\frac{20}{8}\times\left(\frac{104}{56}+\frac{497}{56}-\frac{104}{56}\right)\)
\(=\frac{20}{8}\times\left(\frac{104+497-104}{56}\right)\)
\(=\frac{20}{8}\times\frac{497}{56}\)
\(=\frac{20\times497}{8\times56}=\frac{9940}{448}=\frac{355}{16}\)
