\(\frac{5+55+555+5555}{9+99+999+9999}=\frac{5.\left(1+11+111+1111\right)}{9.\left(1+11+111+1111\right)}=\frac{5}{9}\)\(\frac{5}{9}\)
dấu chấm bạn cứ hiểu là nhân nhé !
\(\frac{5+55+555+5555}{9+99+999+9999}=\frac{5+11x5+111x5+1111x5}{9+11x9+111x9+1111x9}\)\(=\frac{5x5x5x5}{9x9x9x9}=\frac{625}{6561}\)
A = \(\frac{6170}{11106}=\frac{5}{9}\)
A=5+55+555+5555/9+99+999+9999
A=5x1+5x11+5x111+5x1111/9x1+9x11+9x111+9x1111
A=5x(1+11+111+1111)/9x(1+11+111+1111)
A=5/9
\(\frac{5+55+555+5555}{9+99+999+9999}=\frac{5.1+5.11+5.111+5.1111}{9.1+9.11+9.111+9.1111}\)
\(\frac{5.\left(1+11+111+1111\right)}{9.\left(1+11+111+1111\right)}=\frac{5}{9}\)
