You don't have a picture we can help with
Let x = pounds of $12 per pound coffee
then
20-x = pounds of $9 per pound coffee
.
12x + 9(20-x) = 10(20)
12x + 180 - 9x = 200
3x + 180 = 200
3x = 20
x = 20/3
x = 6 and 2/3 pounds of $12 per pound coffee
.
Amount of $9 per pound coffee:
20-x = 20-20/3 = 60/3 - 20/3 = 40/3
or
13 and 1/3 pounds of $9 per pound coffee
Hope this helps! Don’t mind the part I crossed off.
