1\а - 1\2а = 1/а - 1/2а = (2 - 1)/2а = 1/2а
7\3а-3b - 5\2a-2b = 7/3а - 3b - 5/2a + 2b = (14 - 30 + 15b + 6b)/6a = (15b + 6b -16)/6a = 21b - 16/6a = 7b - 8/2a = 7b - 4/a
x\x"2-4 - 2\x+2 = x^2 - 4 - 2/x + 2 = x^2 - 2 -2/x
1\а - 1\2а = 1/а - 1/2а = (2 - 1)/2а = 1/2а
7\3а-3b - 5\2a-2b = 7/3а - 3b - 5/2a + 2b = (14 - 30 + 15b + 6b)/6a = (15b + 6b -16)/6a = 21b - 16/6a = 7b - 8/2a = 7b - 4/a
x\x"2-4 - 2\x+2 = x^2 - 4 - 2/x + 2 = x^2 - 2 -2/x