Linear question

Question

How many gallons each of 30​% alcohol and 10​% alcohol should be mixed to obtain 20 gal of 13​% ​alcohol?

Answer 1

x+y=20

y=20-x

.3x + .1y = .13(20)= 2.6

.3x +.1(20-x)=2.6

.3x +2 -.1x = 2.6

.2x = .6

x = 3 gallons of 30% alcohol

y= 17 gallons of 10% alcohol