Решить уравнение:

a) √x^2-3x=x+3

b) 6/x + 6/x+1 = 5

√x^2 - 3x = x + 3

x^2 - 3x = (x + 3) ^2

x^2 - 3x = x^2 + 6x + 9

x^2 - x^2 - 3x - 6x = 9

- 9x = 9

x = - 1

6/x + 6/x + 1 = 5

6 (x + 1) + 6x = 5x (x + 1)

6x + 6 + 6x = 5x^2 + 5x

12x - 5x - 5x^2 + 6 = 0

- 5x^2 + 7x + 6 = 0

5x^2 - 7x - 6 = 0

D = b^2 - 4ac = 49 + 120 = 169 = 13^2

x1 = (7 + 13) / 10 = 2

x2 = (7 - 13) / 10 = - 0,6