Lamar's coffee shop makes a blend that is a mixture of two types of coffee. type a coffee costs lamar $4.40 per pound, and type b coffee costs $5.60 per pound. this month, lamar made 129 pounds of the blend, for a total cost of $658.80. how many pounds of type b coffee did he use?

Lamar used 76 pounds of type B coffee

Step-by-step explanation:

Let x = the number of pounds of type A coffee

Let y = the number of pounds of type B coffee

Type A coffee costs Lamar $4.40 per pound, and type B coffee costs $5.60 per pound. This means total cost of type A coffee and type B coffee will be

$(4.4x + 5.6y)

This month, Lamar made 129 pounds of the blend, for a total cost of $658.80.

This means the sum of type A coffee and type B coffee for the month is 129 and the total cost is $658.80

The equations deducted are

x + y = 129 - - - - - - - - -1

4.4x + 5.6y = 658.80 - - - - - - - - - - 2

Substituting x = 129 - y in equation 2,

4.4(129 - y) + 5.6y = 658.80

567.6-4.4y + 5.6y = 658.80

-4.4y + 5.6y = 658.80 - 567.6

1.2y = 91.2

y = 91.2/1.2 = 76 pounds

x = 129-y = 129-76

= 53 pounds

Lamar used 76 pounds of type B coffee