Is it True that 80:100 and 40:50 are equal?

$\frac{80}{100},$when divided by 20 (in numerator and denominator), we get

$\frac{4}{5}$. 

Similarly$\frac{40}{50}$ when divided by 10, we get,$\frac{4}{5}$ 

Hence they both are equal, i.e., $\frac{80}{100}=\frac{40}{50}$