Hazel wants to mix 12 pounds of her special blend coffee that will cost her $12.50 per pound. she uses columbian and sumatra coffees which cost her $9.25 and $14.25 per pound.
write an equation that relates all the quantities
how many pounds of each coffee does she need

X - pounds of Columbian coffee;
y - pounds of Sumatra coffee.
9.25 x + 14.25 y = 12.50 ( x + y )
x + y = 12

9.25 x + 14.25 y = 150
x = 12 - y

9.25 ( 12 - y ) + 14.25 y = 150
111 - 9.25 y + 14.25 y = 150
5 y = 150 - 111
5 y = 39
y = 39 : 5
y = 7.8
x = 12 - 7.8
x = 4.2

She needs 4.2 pounds of Columbian coffee and 7.8 pounds of Sumatra coffee.

Answer texture;