Question

tính nhanh : \(\left(\frac{575757}{424242}+\frac{575757}{565656}+\frac{575757}{727272}\right).18\)  

Answer 1

\(=\left(\frac{57}{42}+\frac{57}{56}+\frac{57}{72}\right)\times18\)

\(=\frac{19}{6}\times18=57\)

Answer 2

= (57/42 +57/56 + 57/72),18

=(1/6.7 +1/7.8 +1/8.9).18.57

=(1/6-1/7 +1/7 -1/8 +1/8-1/9).18.57

=(1/6-1/9) .18 .57

=57.3 - 57.2

=57