1/
5/6a - 4/5a + 1 = 1/2a - 2/5.
25/30a - 24/30a + 1 = 15/30a - 2/5.
25/30a - 24/30a - 15/30a = - 2/5 - 5/5.
-14/30a = -7/5.
a = -7/5 : (-14/30),
а = -7/5 * (-30/14),
а = 3,
проверка:
5/6*3 - 4/5*3 + 1 = 1/2*3 - 2/5,
5/2 - 12/5 + 1 = 3/2 - 2/5,
25/10 - 24/10 + 10/10 = 15/10 - 4/10,
11/10 = 11/10
2.
(-0,91) = (x) * (-2,6),
х = -0,91 : (-2,6),
х = 0,35,
проверка:
-0,91 = 0,35 * (-2,6),
-0,91 = -0,91