
William W. answered 05/06/23
Math and science made easy - learn from a retired engineer
Let "A" represent the amount (number of pounds) of Type A coffee and let "B" represent the amount (number of pounds) of Type B coffee.
Then "This month's blend used twice as many pounds of type B coffee as type A" means:
2A = B
And "Type A coffee costs . . . $4.10 per pound, and type B coffee costs $5.65 per pound . . . for a total cost of $539.00" means:
4.10A + 5.65B = 539.00
Since "2A" is the same as "B" (from the 1st equation) then we can substitute "2A" in place of "B" making the 2nd equation:
4.10A + 5.65(2A) = 539.00
4.10A + 11.30A = 539.00
15.40A = 539.00
A = 539.00/15.40
A = 35
So there were 35 pounds of Type A coffee used