Question

Na figura, as retas r,s e t são paralelas. Calcule valor de x (por favor com resolução)

Answer 1

Seguindo o Teorema de Tales, temos:

$\implies \ \ \ \dfrac{12}{x \ + \ 4} \ \ = \ \ \dfrac{8}{6} \\\\\\ \implies \ \ \ 8 \ (x \ + \ 4) \ \ = \ \ 12 \ \cdot \ 6 \\\\ \implies \ \ \ 8x \ + \ 32 \ \ = \ \ 72 \\\\ \implies \ \ \ 8x \ \ = \ \ 72 \ - \ 32 \\\\ \implies \ \ \ 8x \ \ = \ \ 40 \\\\ \implies \ \ x \ \ = \ \ \dfrac{40}{8} \\\\ \implies \ \ \ \boxed{ \boxed{ \ x \ \ = \ \ 5 \ } }$