Answer: 5
Explanation:
There are two similar triangles here, the smaller superimposed on the bigger one. One thing here is that, one of their three sides are parallel to each other .
When the triangles are separated, one side of the bigger triangle = 24, and this correspond to 10 in the smaller triangle.
The size of the other side in the bigger triangle = 2x - 3 + x
 = 3x - 3 
This correspond to x in the smaller triangle.
Now by considering congruent triangles now,
 10/24 = x/3x - 3
Therefore, cross multiply to get the value of x
 10(3x - 3 ) = 24x
Open the brackets and collect like terms, 
 30x - 30 = 24x
 30x - 24x = 30
 6x = 30
Therefore, divide through by 6 x = 5