You can put this solution on YOUR website!
Let c=chocolate coffee
Let h=hazelnut coffee
Since you need a 6 pound mixture of both coffees, you have to add them together, so your first equation will be:
You need a 6 pound mixture that costs 6.40 per pound. For this equation you take the price per coffee multiplied by the type of coffee. And since you need a 6 pound mixture that costs 6.40 per pound, multipy 6.40 by 6 to get the total of the mixture.
From there you can solve by substitution.
2 pounds of chocolate coffee should be used
4 pounds of hazelnut coffee should be used.
Hope that helps.