a is directly proportinal or inversely proportional to b.
http://wiki.answers.com/Q/What_is_the_direct_varia...

It's when two variable quantities have a constant ration. The formula is y=kx, k being
http://www.chacha.com/question/whatmakesadirect...

In equation y = mx, the value of y varies directly with the value of x. In equation y = mx + b, the value of y varies partially with the value of x.
http://answers.yahoo.com/question/index?qid=200907...

My favorites are. guava lemonade. watermelonade. I also like the Blue Bottle lemonade, which they make with yuzu.
http://www.quora.com/Lemonade/Whatarethebestva...
