Question

Bad story ploblem

Answer 1

x of the $20 coffee + 90 of the $60 coffee = $50 x the total amount of pounds used. So...

20x + (90.60) = 50 (x + 90)
20x + 5400 = 50x + 4500 (distribute the 50 on the right side)
900 = 30x (get the x's on the right side, the rest on the left side)
30 = x (divide both sides by 30)

and to test if it's right...

30 pounds of $20 = 600
+ 90 pounds of $60 = 5400

= 120 pounds of $50 = 6000