12х - х - 55 = 011x - 55 = 011x = 55x = 5
8x - 5x - 3 = 63x - 3 = 63x = 9x = 3
2 + 6a + 4a = 9210a = 90a = 9
Therefore, the solutions are x = 5, x = 3, and a = 9.
12х - х - 55 = 0
11x - 55 = 0
11x = 55
x = 5
8x - 5x - 3 = 6
3x - 3 = 6
3x = 9
x = 3
2 + 6a + 4a = 92
10a = 90
a = 9
Therefore, the solutions are x = 5, x = 3, and a = 9.