Question

Escreva o número que deve ser colocado no lugar do de modo a determinar a fração equivalente à fração dada.

Answer 1

Explicação passo-a-passo:

a)

$\sf \dfrac{2}{5}=\dfrac{6}{x}$

$\sf 2x=5\cdot6$

$\sf 2x=30$

$\sf x=\dfrac{30}{2}$

$\sf \red{x=15}$

b)

$\sf \dfrac{3}{4}=\dfrac{x}{20}$

$\sf 4x=3\cdot20$

$\sf 4x=60$

$\sf x=\dfrac{60}{4}$

$\sf \red{x=15}$

c)

$\sf \dfrac{5}{6}=\dfrac{x}{42}$

$\sf 6x=5\cdot42$

$\sf 6x=210$

$\sf x=\dfrac{210}{6}$

$\sf \red{x=35}$

d)

$\sf \dfrac{5}{7}=\dfrac{x}{56}$

$\sf 7x=5\cdot56$

$\sf 7x=280$

$\sf x=\dfrac{280}{7}$

$\sf \red{x=40}$

e)

$\sf \dfrac{10}{14}=\dfrac{5}{x}$

$\sf 10x=14\cdot5$

$\sf 10x=70$

$\sf x=\dfrac{70}{10}$

$\sf \red{x=7}$

Answer 2

Resposta:

a)

\sf \dfrac{2}{5}=\dfrac{6}{x}

5

2

=

x

6

\sf 2x=5\cdot62x=5⋅6

\sf 2x=302x=30

\sf x=\dfrac{30}{2}x=

2

30

\sf \red{x=15}x=15

b)

\sf \dfrac{3}{4}=\dfrac{x}{20}

4

3

=

20

x

\sf 4x=3\cdot204x=3⋅20

\sf 4x=604x=60

\sf x=\dfrac{60}{4}x=

4

60

\sf \red{x=15}x=15

c)

\sf \dfrac{5}{6}=\dfrac{x}{42}

6

5

=

42

x

\sf 6x=5\cdot426x=5⋅42

\sf 6x=2106x=210

\sf x=\dfrac{210}{6}x=

6

210

\sf \red{x=35}x=35

d)

\sf \dfrac{5}{7}=\dfrac{x}{56}

7

5

=

56

x

\sf 7x=5\cdot567x=5⋅56

\sf 7x=2807x=280

\sf x=\dfrac{280}{7}x=

7

280

\sf \red{x=40}x=40

e)

\sf \dfrac{10}{14}=\dfrac{5}{x}

14

10

=

x

5

\sf 10x=14\cdot510x=14⋅5

\sf 10x=7010x=70

\sf x=\dfrac{70}{10}x=

10

70

\sf \red{x=7}x=7