To write; -12.405 as a mixed number:
First keep the whole number aside
That is; you shoul keep 12 aside
Then you will be left with 0.405
Write 0.405 over 1
That is;
![(0.405)/(1)](https://img.qammunity.org/2023/formulas/mathematics/college/4nf77idx9fre7d7y4llpp5i2ijw0frvnfj.png)
Multiply 1000 be the numerator and denominator
That is;
![\frac{0.405\text{ }*1000}{1\text{ }*1000}](https://img.qammunity.org/2023/formulas/mathematics/college/j812eatj30z5lj97kgmg0e7v7tgikheyhf.png)
![=(405)/(1000)](https://img.qammunity.org/2023/formulas/mathematics/college/lsogwujx2ojcs95xkm38wjcio2kfe5bu3o.png)
We can go ahead and reduce the fraction;
![=(81)/(200)](https://img.qammunity.org/2023/formulas/mathematics/college/jkvtku8mrulfbrjqk2c8g3kxr39kk7plh5.png)
Hence the mixed number is;
![-12.405\text{ = -12}(81)/(200)](https://img.qammunity.org/2023/formulas/mathematics/college/4sejz1naymh8nzgs50fb9aiv941r1hzzyr.png)