Question

Tính nhanh

B=5/2.1+4/1.11+3/11.2+1/2.15+13/15.4

Answer 1

B = 7(5/2.7 + 4/7.11 + 3/11.14 + 1/14.15 + 13/15.28)

B = 7.(1/2 - 1/7 + 1/7 - 1/11 + 1/11 - 1/14 + 1/14 - 1/15 + 1/15 - 1/28)

B = 7.( 1/2 - 1/28)

B = 7. 13/28

B = 13/4

k mk đi!

Answer 2

why! tại sao có thể làm như vậy

Answer 3

=7.(5/2.7+4/7.11+3/11.14+1/14.15+13/15.28)

=7.(1/2-1/7+1/7-1/14+1/14-1/15+1/15-1/28)

=7.(1/2-1/28)

=13/4