Deandres coffee shop makes a blend that is a mixture of two types of coffee. type a coffee costs deandre $5.95 per pound, and type b coffee costs $4.50 per pound. this month, deandre made 136 pounds of the blend, for a total cost of $684.50. how many pounds of type b coffee did he use?

Let b represent the number of pounds of type B coffee used. Then the cost of the blend can be computed as
.. (136 -b)*5.95 +b*4.50 = 684.50
.. 809.20 -1.45b = 684.50 . . . . . . . eliminate parentheses
.. 124.70 = 1.45b . . . . . . . . . . . . . . . add 1.45b-684.50
.. 86 = b . . . . . . . . . . . . . . . . . . . . . . divide by 1.45

Deandre used 86 pounds of type B coffee in his blend.