(I have a deadline in 3 hours :c ) Ann's Coffee Shop makes a blend that is a mixture of two types of coffee. Type A coffee costs
Ann $4.35 per pound, and type B coffee costs $5.40 per pound. This month's blend used three times as many pounds of type B coffee as type A, for a total cost of $780.90. How many pounds of type A coffee were used?
The two equations would be:
4.35a + 5.40b = 780.90
and b = 3a
substitute:
4.35a + 5.40(3a) = 780.90
Multiply:
4.35a + 16.2a = 780.90
add like terms:
20.55a = 780.9
divide by 20.55:
a = 38
substitute into the other equation:
b = 3(38)
multiply:
b = 114
This means that 38 pounds of coffee were used for type A (variable a) and 114 pounds of coffee were used for type B (variable b)
A=3B 4.35A+5.40B=780.95 Substitute 3B into A for the second equation: 4.35(3B)+5.40B=780.90 13.05B+5.40B=780.90 18.45B=780.90 B=42.33 Plug into equation 1: A=3B A=3(42.33) A=126.98
