Question

calcule o valor de x pelo teorema de tales

Answer 1

2/5=X/4
5X=2.4
5X=8
X=8/5

Answer 2

$\large \boxed{ \begin{array}{l} \dfrac{2}{5} = \dfrac{x}{4} \\ \\ 5x = 2 \times 4 \\ 5x \: = \: 8 \\ x = 8/5\end{array}}$