Question

There are 21 males in the algebra 1 class. If 75% is female, how many students are there in the class?

Answer 1

$x-\ female\\\\ y-all\ students\\\\ z=21\\ x=0,75y\\\\ x+z=y\\ 0,75y+21=y\ \ \ |subtract\ 0,75y\\ 21=0,25y\ \ \ | divide\ by\ 0,25\\y=84\\\\There\ are\ 84\ students\ in\ class.$