Step-by-step explanation:
0.4 x + 3.9 = 5.7
hope 0.4 x = 5.78 - 3.9
0.4x = 1.88
x = 1.88/0.4
x = 4.7
Yes because it goes up and back down
Answer:
y = 60
Step-by-step explanation:
From the information we get:
x quantity of 4 dollars coffee used in the mix
y quantity of 7 dollars coffee used in the mix
For the quantity of coffee to be sold a 7 $/pound ( 90 pounds)
Then 6*90 = 540 $
Therefore
x + y = 90 and
4*x + 7*y = 540
A two equations system we solve for x and y
y = 90 - x
4*x + 7* ( 90 - x ) = 540
4*x + 630 - 7*x = 540
- 3*x = - 90
x = 30 pounds and
y = 90 - 30
y = 60
We should use 60 pounds of the seven $ coffee
