Answer:
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
