\(18\times\left(\frac{37}{42}+\frac{37}{56}+\frac{37}{72}\right)\)
\(=18\times\left(37\times\frac{1}{42}+37\times\frac{1}{56}+37\times\frac{1}{72}\right)\)
\(=18\times\text{[}37\left(\frac{1}{42}+\frac{1}{56}+\frac{1}{72}\right)\text{]}\)
\(=18\times\text{[}37\times\frac{1}{18}\text{]}\)
\(=18\times\frac{37}{18}=37\)
18 x [ 37/42+37/56+37/72]
= 18 x 37/18
= 37
~ Học tốt nha ~
k cho mk:>>
\(18\times\left[\frac{37}{42}+\frac{37}{56}+\frac{37}{72}\right]\)
\(=18\times\left[\frac{37}{6\times7}+\frac{37}{7\times8}+\frac{37}{8\times9}\right]\)
\(=18\times\left[37\left\{\frac{1}{6\cdot7}+\frac{1}{7\cdot8}+\frac{1}{8\cdot9}\right\}\right]\)
\(=18\times\left[37\left\{\frac{1}{6}-\frac{1}{7}+\frac{1}{7}-\frac{1}{8}+\frac{1}{8}-\frac{1}{9}\right\}\right]\)
\(=18\times\left[37\left\{\frac{1}{6}-\frac{1}{9}\right\}\right]\)
\(=18\times\left[37\times\frac{1}{18}\right]\)
\(=18\times\frac{37}{18}=37\)
