Plz help i want to learn how to do this math


Jenny's Coffee Shop makes a blend that is a mixture of two types of coffee. Type A coffee costs Jenny 5.25
per pound, and type B coffee costs 4.15
per pound. This month, Jenny made 150
pounds of the blend, for a total cost of
642.60. How many pounds of type B coffee did she use?

Respuesta :

In order to know the answer, you would have to set up a system of equations:

Given that type A coffee costs $4.15 per pound
(4.15x)
Given that type B coffee costs $5.25 per pound
(5.25y)
And that the total cost of it all was $642.60

[tex]4.15x + 5.25y = 642.60[/tex]
Also, the amount of pounds, represented by x and y add up to 150 pounds total:

[tex]x + y = 150[/tex]
aka9
A+B=167lbs
A=167lbs-B
$4.35A+$5.70B=$846.60 Substitute for A
$4.35(167lbs-B)+$5.70B=$846.60
$726.45-$4.35B+$5.70B=$846.60 Subtract $726.45 from each side.
$1.35B=$120.15 Divide each side by $1.35.
B=89 lbs
ANSWER: The mix contained 89 pounds of Type B coffee.
CHECK:
167lbs-89lbs=78 lbs She used 78 pounds of Type A coffee.
$4.35A+$5.70B=$846.60
$4.35(78)+$5.70(89)=$846.60
$339.30+$507.30=$846.60
$846.60=$846.60