Question

What is the value of x?

Answer 1

Answer:  $x=2$

Step-by-step explanation:

To solve this exercise you must apply the Intersecting secan theorem.

Then, according to this theorem, you can know that:

$EC*ED=EB*EA$

Therefore, you must substitute the values shown in the figure attached, as following:

$(x+4)(x+4+1)=(x+1)(x+1+11)$

Now you can solve for x, as you can see below:

$(x+4)(x+4+1)=(x+1)(x+1+11)\\\\(x+4)(x+5)=(x+1)(x+12)\\\\\\x^2+5x+4x+20=x^2+12x+x+12\\\\x^2+9x+20=x^2+13x+12\\x^2-x^2+9x-13x=12-20\\-4x=-8\\x=2$