What is the similarity between numbers 85 17 19 4 and 2?

My favorite songstress gives away 25% of this side of her signature fragrance collection to her charity last month her sales were 1200 how much of her sales did she donate

What are the constants in this expression? -10.6+9/10+2/5m-2.4n+3m

Equation for the calculation double 2 and then add 5