Respuesta :

Answer:

x = 28

Step-by-step explanation:

If a line parallel to one side of a triangle intersects the other two sides of the triangle, then the line divides these two sides proportionally.

Then x/(x +10) = 42/(42 +15)

x(57) = 42(x + 10)

57x = 42x + 420

15x = 420

x = 28