How many liters each of a 40​% antifreeze solution and a 80​% antifreeze solution must be mixed to make 8 liters of a 50​% antifreeze​ solution?

Answer 1

Needed: Two equations

Equation 1. x + y = 8 Equation 2. .40x + .80y = 8(.5)

This is a system of equations. You can use the substitution method or the elimination method. I will presume you know how to solve a system of equations in two variables...

Answer 2

x(40) + y(80) = 8(50)

x + y = 8, y = 8 - x

Substitute:

40x + 80(8 - x) = 400

40x + 640 - 80x = 400

-40x = -240

x = 6

y = 2