Question

tính nhanh 5+55+555+5555/7+77+777+7777

Answer 1

\(=\frac{5}{7}\)

Cho mk xin cái li ke

Answer 2

a, = 5x1+5x11+5x111+5x1111

=5 x (1+11+111+1111)

=5 x 1234

=6170

b, giống câu trên.

Answer 3

\(\frac{5.\left(1+11+111+1111\right)}{7.\left(1+11+111+1111\right)}=\frac{5}{7}\)

k cho mik nha

Answer 4

\(\frac{5+55+555+5555}{7+77+777+7777}\)

\(=\frac{5.1+5.11+5.111+5.1111}{7.1+7.11+7.111+7.1111}\)

\(=\frac{5.\left(1+11+111+1111\right)}{7.\left(1+11+111+1111\right)}\)

\(=\frac{5}{7}\)