Answer: He used 91 pounds of type A coffee
Step-by-step explanation:
Let x represent the number of pounds of type A coffee used
Let y represent the number of pounds of type B coffee used
This month, Dante made 156 pounds of the blend. This means that
x + y = 156
y = 56 - x
Type A coffee costs Dante $4.30 per pound, and type B coffee costs $5.50 per
pound. This month, the total cost the blend was $748.80. This means that
4.3x + 5.5y = 748.8
We would substitute y = 56 - x into 4.3x + 5.5y = 748.8. We have
4.3x + 5.5(156 - x) = 748.8
4.3x + 858 - 5.5x = 748.8
4.3x - 5.5x = 748.8 - 858
- 1.2x = - 109.2
x = - 109.2/- 1.2
x = 91
He used 91 pounds of type A coffee