Seven less than 1/4 of a number is 9. The phrase a number means an arbitrary variable, let's call it x. x 1/4 of a number means we multiply x by 1/4: x/4 Seven less than this means we subtract 7 from x/4: x/4 - 7 The word is means an equation, so we set x/4 - 7 equal to 9: x/4 - 7 = 9