Question

tinh nhanh 

1/4*3+1/5*4+1/6*5+1/7*6=

Answer 1

=1/3 - 1/4 + 1/4 - 1/5 + 1/5 - 1/6 +1/7 

=1/3 - 1/6 + 1/7

= 1/6 +1/7

=13/42

Answer 2

=\(\frac{1}{3}\) - \(\frac{1}{4}\) + \(\frac{1}{4}\) - \(\frac{1}{5}\) + \(\frac{1}{5}\) - \(\frac{1}{6}\) +\(\frac{1}{7}\)

=\(\frac{1}{3}-\frac{1}{6}+\frac{1}{7}\)

= \(\frac{1}{6}+\frac{1}{7}\)

=\(\frac{13}{42}\)

Answer 3

hoang tu may trang giai thich gium to voi

cho to hoi co phai cau hoc lop 7 khong

Answer 4

    

 

Answer 5

1234567890