4 2/9 × х + 3 5/14 = 6 11/21
4 2/9 × х = 6 11/21 - 3 5/14
4 2/9 × х = 6 22/42 - 3 15/42
4 2/9 × х = 3 7/42
4 2/9 × х = 3 1/6
х = 3 1/6 : 4 2/9 = 19/6 : 38 /9 = 19/6 * 9/38 = (1*3)/(2*2)
х= 3/4
4 2/9 × 3/4 + 3 5/14 = 6 11/21
38/9 × 3/4 + 47/14 = 6 11/21
19/6 + 47/14 = 6 11/21
(133 + 141)/42 = 6 11/21
274/42 = 6 11/21
137/21 = 6 11/21
6 11/21 = 6 11/21