Question

Nas figuras, a // b // c //, calcule o valor de x. Preciso da conta.

Answer 1

a)

$\frac{2}{4}  =  \frac{3}{x}  \\ 2x = 3 \times 4 \\ 2x = 12 \\ x = 12 \div 2 \\ x = 6$

b)

$\frac{4}{12}  =  \frac{x}{21} \\ 12x = 21 \times 4 \\ 12x = 84 \\ x = 84 \div 12 \\ x = 7$   

Espero ter ajudado  

Answer 2

Resposta:

A)

4/x = 12/21

12x = 21 × 4

12x = 84

x = 84/12

x = 7

B)

10/(3x + 1) = 15/(5x - 2)

10(5x - 2) = 15(3x + 1)

50x - 20 = 45x + 15

50x - 45x = 15 + 20

5x = 35

x = 35/5

x = 7

Espero que !!