(11/15)х + 9/10 = 8/15
(11/15)х = 8/15 - 9/10
(11/15)х = 16/30 - 27/30
(11/15)х = -11/30
х = -11/30 : 11/15
х = -11/30 · 15/11 = -15/30
х = -1/2
(11/15)х + 9/10 = 8/15
(11/15)х = 8/15 - 9/10
(11/15)х = 16/30 - 27/30
(11/15)х = -11/30
х = -11/30 : 11/15
х = -11/30 · 15/11 = -15/30
х = -1/2