Question

1 - Calcule o termo desconhecido nas proporções:
a) X/6=16/12

b) 7/5=5/y

c) 3x/4=2/6

d) 20-x/20=2/5

e) 4/5=20/x+1

f) x/10=2/5​

Answer 1

Explicação passo-a-passo:

Boa noite Samuel ☺️

Vamos lá?

A)

$\dfrac{x}{6} = \dfrac{16}{12}$

Multiplique cruzado

$12 \times x = 16 \times 6$

$12x = 96$

$x = \dfrac{96}{12}$

X=> 8✓

B)

$\dfrac{7}{5} = \dfrac{5}{y}$

Multiplique cruzado

$7 \times y = 5 \times 5$

$7y = 25$

$y = \dfrac{25}{7}$✓

C)

$\dfrac{3x}{4} = \dfrac{2}{6}$

Multiplique cruzado

$3x \times 6 = 2 \times 4$

$18x = 8$

$x = \dfrac{8}{18}$

$x = \dfrac{8 {}^{ \div 2} }{18 {}^{ \div 2} }$

$x = \dfrac{4}{9}$✓

D)

$\dfrac{20 - x}{20} = \dfrac{2}{5}$

Multiplique cruzado

$5(2 0 - x) = 2 \times 20$

$100 - 5x = 40$

$- 5x = 40 - 100$

$- 5x = - 60$

$- 5x = - 60( - 1)$

$5x = 60$

$x = \dfrac{60}{5}$

X=> 12✓

E)

$\dfrac{4}{5} = \dfrac{20}{x + 1}$

Multiplique cruzado

$4(x + 1) = 20 \times 5$

$4x + 4 = 100$

$4x = 100 - 4$

$4x = 96$

$x = \dfrac{96}{4}$

X=> 24✓

F)

$\dfrac{x}{10} = \dfrac{2}{5}$

Multiplique cruzado

$5 \times x = 10 \times 2$

$5x = 20$

$x = \dfrac{20}{5}$

X=> 4✓

Espero ter ajudado em algo ☺️