The triangles are similar.
What is the value of x?
x =

Answer:
x = 23
Step-by-step explanation:
Since the triangles are similar then the ratios of corresponding sides are equal, that is
[tex]\frac{39}{x-10}[/tex] = [tex]\frac{36}{12}[/tex] = [tex]\frac{15}{5}[/tex] = 3
multiply both sides by (x - 10)
3(x - 10) = 39 ( divide both sides by 3 )
x - 10 = 13 ( add 10 to both sides )
x = 23