Question

3. Resolva as seguintes proporções:
a x/5=21/35
b 10/7=50/x
c 1/7=x-6/49
d 5x+3/10= -21/30

Answer 1

a)

x/5 = 21/35

x = 21/7

x = 3

b)

10/7 = 50/x

1/7 = 5/x

x = 7 . 5

x = 35

c)

1/7 = (x - 6)/49

x - 6 = 7

x = 7 + 6

x = 13

d)

(5x + 3)/10 = - 21/30

5x + 3 = - 7

5x = - 7 - 3

5x = - 10

x = - 10/5

x = - 2

Resposta:

a) x = 3

b) x = 35

c) x = 13

d) x = - 2

Answer 2

Resposta:

a) x = 3     b) x = 35      c) x = 13       d) x = - 2

Explicação passo-a-passo:

Boa noite!

a)

$\dfrac{x}{5} = \dfrac{21}{35}\\\\35.x = 21.5\\\\35x=105\\\\x=\frac{105}{35}\\\\ x = 3$

b)

$\dfrac{10}{7} = \dfrac{50}{x}\\\\10.x = 7.50\\\\10x=350\\\\x=\frac{350}{10}\\\\ x = 35$

c)

$\dfrac{1}{7} = \dfrac{x-6}{49}\\\\7.(x-6) = 1.49\\\\7x-42 = 49\\\\7x = 49+42\\\\7x=91\\\\x=\frac{91}{7}\\\\ x = 13$

d)

$\dfrac{5x+3}{10} = \dfrac{-21}{30}\\\\30.(5x+3) = -21.10\\\\150x+90 = -210\\\\150x = -210-90\\\\150x=-300\\\\x=\frac{-300}{150}\\\\ x = -2$

Espero ter ajudado!