5 11/14 х - 8/15=5/21

3 х=2/9

18/49: х=6/35

210 (511x/14-8/15) = 210*5/21 210*511x/14-210*8/15=210*5/21 15*511-14*8=10*5 7665x-112=50 7665x=162 x 162/7665 = 54/2555; 2) 9*3x=9*2/9 27x=2 x = 2/27; 3) 18/49:x=6/35 x*18/49*x=x*6/35 18/49=x*6/35 245*18/49=245x*6/35 5*18=7x*6 90=7x*6 90 = 42x x=90/42=15/7

5 11/14 х-8/15=5/21 3 х=2/9 18/49:х=6/35

5 11/14 х=5/21+8/15 х=2/9:3 х=18/49:6/35

5 11/14 х=81/105 х=2/27 х=2 1/7

х=81/105:5 11/14

х=2/15