`4/7xx3/7+4/5xx6/7-4/5xx7/14`
`=4/7xx3/7+4/5xx(6/7-7/14)`
`=4/7xx3/7+4/5xx5/14`
`=12/49+2/7`
`=26/49`
=4/7x3/7+4/5x(6/7-7/14)
=4/7x3/7+4/5x5/14
=12/49+2/7
=26/49
đây là bài của cô giáo mình cho mình làm
\(\dfrac{4}{7}\times\dfrac{3}{7}+\dfrac{4}{5}\times\dfrac{6}{7}-\dfrac{4}{5}\times\dfrac{7}{14}\)
\(=\dfrac{4}{7}\times\dfrac{3}{7}+\dfrac{4}{5}\times\left(\dfrac{6}{7}-\dfrac{7}{14}\right)\)
\(=\dfrac{4}{7}\times\dfrac{3}{7}+\dfrac{4}{5}\times\dfrac{5}{14}\)
\(=\dfrac{4}{7}\times\dfrac{3}{7}+\dfrac{4}{14}\)
\(=\dfrac{4}{7}\times\dfrac{3}{7}+\dfrac{4}{7}\times\dfrac{1}{2}\)
\(=\dfrac{4}{7}\times\left(\dfrac{3}{7}+\dfrac{1}{2}\right)\)
\(=\dfrac{4}{7}\times\dfrac{13}{14}\)
\(=\dfrac{26}{49}\)
| #Sahara |
=4/7x3/7+4/5x(6/7-7/14)
=4/7x3/7+4/5x5/14
=12/49+2/7
=26/49