Question

1 10 Sendo a // b // c, calcule o valor de x em cada item a) 12 3=13 18 b) 20 a b c) 21 S​

Answer 1

Resposta:

b)

$\dfrac{15}{x}=\dfrac{20}{10}\\ \\ multiplica~~cruzado\\ \\ \\ 20x=15.(10)\\ \\ 20x=150\\ \\ x=\dfrac{150}{20}\\ \\ \\\boxed{ x=7,5}$

c)

$\dfrac{9}{9+5}=\dfrac{x}{21}\\ \\ \\ \dfrac{9}{14}=\dfrac{x}{21}\\ \\\\ 14x=9.(21)\\ \\ 14x=189\\ \\ x=\dfrac{189}{14}\\ \\ \\ \boxed{x=13,5}$