Question

calcule o valor do x:​

Answer 1

Nesse exercício,vamos aplicar o Teorema de Tales

Fazemos:

$\Large{\boxed{\sf \dfrac{4}{12}=\dfrac{x}{21}}}$

$\Large\red{\boxed{\orange{\boxed{\blue{\begin{array}{l} \tt 12X=21.4 \\ \\ \tt 12X=84 \\ \\ \tt X=\dfrac{84}{12} \\ \\ \tt X=7 \end{array}}}}}}$

Logo temos a Resposta:

$\Large\boxed{\blue{\text{\sf 7}}}\Longleftarrow$

$\Large{\text{\tt Bons\:estudos}}$

$\bf\large{\underline{\qquad \qquad \qquad \qquad \qquad \qquad \quad }}\LaTeX$✍

$\sf(\purple{+}~\red{cores}~\blue{com}~\pink{o}~\orange{App}~\green{Brainly})$

Answer 2

$\large \boxed{ \begin{array}{l} \rm \dfrac{4}{12} = \dfrac{x}{21} \\ \\ \rm \: 12x = 21 \times 4 \\ \rm \: 12x \: = \: 84 \\ \rm \: x = 84/12 \\ \boxed{ \rm x = 7}\end{array}}$