Question 512362
Coffee1=x lb
Coffee2=30 lb
Mixture=30+x lb

Price per pound Coffee1 = $30
Price per pound Coffee2 = $70
Price per pound Mixture = $40

Coffee1*Price + Coffee2*Price=Mixture*Price
(x*30)+(30*70)=(30+x)40
30x+2100=1200+40x
30x-40x=1200-2100
-10x=-900
-10x/-10=-900/-10
x=90
90 pounds of the $30 coffee should be used