-0,8+(-1/9) как решить?

-8/10-1/9=-72/90-10/90=-82/90=-41/45

[latex]- \frac{8}{10}-\frac{1}{9}=-\frac{72}{90}-\frac{10}{90}=-\frac{82}{90}=- \frac{41}{45} [/latex]