x=(1-a)/(1+a) x+xa=1-a a=(1-x)/(1+x) y=(2-3a)/(3-2a) 3y-2ay=2-3a a=(2-3y)/(3-2y) (1-x)/(1+x)=(2-3y)/(3-2y) (1-x)(3-2y)=(2-3y)(1+x) 3-3x-2y+2xy=2-3y+2x-3xy 1+5xy=-y+5x 5xy+y=5x-1 y=(5x-1)/(5x+1)