Respuesta :

(x+4)(x+4+1) = (x+1)(x+1+11)
(x+4)(x+5) = (x+1)(x+12)
x^2 + 4x+5x+20=x^2+x+12x+12
9x + 20 = 13x + 12
 13x-9x = 20-12
        4x = 8
          x = 2
The equation of 2 secants and a circle is;

EC*ED = EB*EA

EC= X+4;  ED = X+4+1 ; EB=X+1; EA= X+1+11; IN SHORT:

(x+4).(x+5) = (x+1).(x+12)

x²+9x+20 = x²+13x+12

x²+9x-x²-13x = 12-20
 -4x = -8

4x = 8



and x = 2