Answer:
Step-by-step explanation:
Alright, lets gets started.
Suppose she mixes x pounds of coffee of $ 60 a pound.
So, the cost of that coffee = [tex]60x[/tex]
Merchant has 50 pounds of coffee worth $ 90 a pound, hence the cost of this second coffee = [tex]90*50=4500[/tex]
The mixture she get, is worth $ 70 and the weight of this mixture will be [tex](x+50)[/tex]
So, the cost of mixture will be = [tex]70*(x+50)[/tex]
Addition of both coffees will be equal to the mixture, so
[tex]60x + 4500 = 70(x+50)[/tex]
[tex]60x + 4500 = 70x + 3500[/tex]
Subtracting 60 x in both sides
[tex]4500=10x + 3500[/tex]
Subtracting 3500 in both sides
[tex]10x = 1000[/tex]
Dividing 10 in both sides
x = 100 pounds
It means she needs to add 100 pounds of that coffee. : Answer
Hope it will help :)
