Respuesta :

Answer:

C

Step-by-step explanation:

The 3 triangles are all similar.

Using the 2 inside then the ratios of corresponding sides are equal, that is

[tex]\frac{x}{3}[/tex] = [tex]\frac{12}{x}[/tex] ( cross- multiply )

x² = 36 ( take the square root of both sides )

x = [tex]\sqrt{36}[/tex] = 6 → C

Answer:

C) x = 6

because this is a right triangle

=> we have:

(12² + x²)(3² + x²) = (15x)²

<=> 1296 + 153x² + x⁴ = 225x²

<=> x⁴ - 72x² + 1296 = 0

<=> (x² - 36)² = 0

<=> x² = 36

=> x = 6