Question

Rút gọn phân số sau:

\(\frac{19999999999}{99999999995}\)

Answer 1

99999999995=19999999999x5

=>\(\frac{\text{19999999999}}{99999999995}=\frac{\text{19999999999}}{\text{19999999999.5}}=\frac{1}{5}\)

 

Answer 2

1/5

Answer 3

Đặt A=\(\frac{19999999999}{99999999995}\)

Xét tử số: 19999999999=2000000000-1=2.10¹⁰-1

Xét mẫu số: 99999999995=100000000000-5=10.10¹⁰-5=5(2.10¹⁰-1)

Suy ra A=\(\frac{2.10^{10}-1}{\text{ }5\left(2.10^{10}-1\right)}\)=\(\frac{1}{5}\)