(11 7/15 + x) - 8 7/15 = 6 8/15
11 7/15 + x = 6 8/15 + 8 7/15
11 7/15 + x = 15
x = 15 - 11 7/15
x = 3 8/15
(11 7/15+х)-8 7/15=6 8/15
11 7/15+х=6 8/15+8 7/15
11 7/15+х=15
х=15-11 7/15
х=3 8/15
