Question 1140605
let x = the number of gallons of 76% oxygen.


let y = the number of gallons of 49% oxygen.


you want 45 gallons of 73% oxygen.


you have 2 equations that need to be solved simultaneously.


they are:


x + y = 45
.76 * x + .49 * y = .73 * 45


simplify to get:


x + y = 45
.76 * x + .49 * y = 32.85


i'll use elimination as the method to solve these 2 equations simultaneously.


multiply both sides of the first equation by .76 and leave the second equation as is to get:


.76 * x + .76 * y = 34.2


.76 * x + .49 * y = 32.85


subtract the second equation from the first to get:


.27 * y = 1.35


solve for y to get:


y = 5.


since x + y = 45, then x = 40


your solution should be that x = 40 and y = 5.


replace x and y in the second original equation to get:


.76 * 40 + .49 * 5 = 32.85 which becomes 32.85 = 32.85, confirming the solution is correct.


32.85 / 45 = .73 = 73%


the requirements of the problem are satisfied.


your solution is that you need to mix 40 gallons of 76% oxygen with 5 gallons of 49% oxygen to get 45 gallons of 73% oxygen.