Answer:
94 pounds
Step-by-step explanation:
Let "a" represent the weight of type A coffee Charlie used. Then 150-a is the weight of the type B coffee. The total cost of the blend is then ...
... 4.85a +5.95(150 -a) = 789.10
... -1.10a +892.50 = 789.10 . . . . . . simplify
... -1.10a = -103.40 . . . . . . . . . . . . . .subtract 892.50
... a = 94 . . . . . . . . . . . . . . . . . . . . . divide by -1.10
Charlie used 94 pounds of type A coffee.
