If the two solutions of the equation x + 2x = C + 2C about X are x = C, x = 2c, then the solution of the equation x + 2x − 1 = a + 2A − 1 about X is () A. a，2aB. a-1，2a−1C. a，2a−1D. a，a+1a−1

If the two solutions of the equation x + 2x = C + 2C about X are x = C, x = 2c, then the solution of the equation x + 2x − 1 = a + 2A − 1 about X is () A. a，2aB. a-1，2a−1C. a，2a−1D. a，a+1a−1

X + 2x − 1 = a + 2A − 1, that is, X-1 + 2x − 1 = A-1 + 2A − 1, then X-1 = A-1 or 2A − 1 is solved as follows: X1 = a, X2 = 2A − 1 + 1 = a + 1a − 1, so D is selected

If equation 2 (x-a) / a (x-1) = - 1 / 5, find the value of A

It is known that: - 5 × (2x-2a) = ax-a, that is - 10x + 10A = ax-a. so (11-x) a = 10x, so a = 10x / (11-x). Because there are two unknowns, we can only use X to express a

Given x + y = - 4, xy = - 12, find the value of Y + 1x + 1 + X + 1y + 1

The original formula = (y + 1) 2 + (x + 1) 2 (x + 1) (y + 1) = x2 + Y2 + 2 (x + y) + 2XY + X + y + 1 = (x + y) 2 − 2XY + 2 (x + y) + 2XY + X + y + 1 ∵ x + y = - 4, xy = - 12, the original formula = 16 + 24 − 8 + 2 − 12 − 4 + 1 = − 3415