a merchant has coffee worth $20 a pound that she wishes to mix with 70 pounds of coffee worth $90 a pound to get a mixture that is worth $30 a pound. How many pound of coffee should be used.

Question

hero · Answer

Solve using methods for systems of equations

anonymous · Answer

okay

anonymous · Answer

thanks alot

hero · Answer

Did you solve it yet? What did you get for x and y?

hero · Answer

Total Pounds of Coffee:   
x + 70  = y

Total Cost of Coffee:
20x + 90(70) = 30y

x + 70 = y
20x + 6300 = 30y
20(y - 70) + 6300 = 30y
20y - 1400 + 6300 = 30y

6300 - 1400 = (30 - 20)y
4900 = 10y
490 = y