Answer:
[tex]x = 13[/tex]
Step-by-step explanation:
Since the two triangles are similar, then their similarity ratio:
[tex] \frac{12}{48} = \frac{x}{52} [/tex]
[tex] \frac{1}{4} = \frac{x}{5} [/tex]
[tex]4x = 52[/tex]
Divide both sides by 4
[tex]x = 13[/tex]