Zad 11 str 221 PROSZĘ NA JUTRO DAJE NAJJJJJJJJJJJJJJJ

a) 2x-3y=1 -3y=1-2x /:(-3) y=1-2x/-3 b) x/4-y/6=5/12 -y/6=5/12-x/4 /*6 -y=5/2-3x/2 y= -5/2+3x/2 c) y-x-y/3=7 /*3 3y -x-y=21 3y-y=21+x 2y=21+x /:2 y= 21+x/2