Question

utilizando o teorema de tales calcule o valor de x

Answer 1

$\frac{4}{8} = \frac{18 - x}{x} \\ \frac{1}{2} = \frac{18 - x}{x} \\ 36 - 2x = x \\ 3x = 36 \\ x = \frac{36}{3} \\ x = 12$