Question

Respondam por favor é pra hoje!

1) Calcule:
A) 5/6+3/4-7/8=
B) ×+5/5+2×-3/10-3×+6/4=

2) Escreva na forma de porcentagem:
a) 1/8=
b) 9/6
c) 0,345=

3) Calcule:
a) 34% de 5%=
b) 75% de 44%=
c) 90% de 65%=

Answer 1

1)

a)

$\mathsf{\dfrac{5}{6}+\dfrac{3}{4}-\dfrac{7}{8}=\dfrac{20+18-21}{24}=\dfrac{17}{24}}$

b)

$\mathsf{\dfrac{5}{5}+2\times(-\dfrac{3}{10})+\dfrac{6}{4}}\\\mathsf{\dfrac{5}{5}-\dfrac{3}{5}+\dfrac{6}{4}=\dfrac{20-12+30}{20}=\dfrac{38}{20}}$

$\mathsf{\dfrac{19}{10}}$

2)

a)

$\mathsf{\dfrac{1}{8}=0,125\times100=12,5\%}$

b)

$\mathsf{\dfrac{9}{6}=1,5\times100=150\%}$

c)

$\mathsf{0,345\times100=34,5\%}$

3)

a)

$\mathsf{34\%\,de\,5\%=0,34.0,05=0,017=1,7\%}$

b)

$\mathsf{75\%\,de\,44\%=0,75.0,44=0,33=33\%}$

c)

$\mathsf{90\%\,de\,65\%=0,9.0,65=0,585=58,5\%}$

Answer 2

Resposta:

Explicação passo-a-passo:

Calcule:

A) 5/6+3/4-7/8=

= (4.5+6.3 - 3.7)/24

= (20+18-21)/24

= (20-3)/24

= 17/24

R.: 17/24

----------------

6,4,8: 2

3,2,4: 2

3,1,2: 2

3,1,1: 3

1,1,1

= 2.2.2.3

= 24

---------------

B) ×+5/5+2×-3/10-3×+6/4=

(x+5)/5 + (2x-3)/10 - (3x+6)/4

[4(x-5) + 2.(2x-3) - 5(3x+6)]/20

[4x-20 + 4x - 6 - 15x - 30]/20

= (-7x -56)/20

R.:

(-7x -56)/20

==================

Obs.:

Essa (b) tem a versão do (X) que nao ficou clara:

= ×+5/5+2×-3/10-3×+6/4=

= x+2x-3x + 5/5 - 3/10 + 6/4 (:2)/(:2)

= 1 - 3/10 + 3/2

= (10.1 - 3 + 5.3)/10

= (10-3+15)/10

= 22/10 : 2/2

= 11/5

===============

________________

MMC = 20

5,10,4: 2

5,5,2: 2

5,5,1: 5

1,1,1

= 2.2.5

= 20

2) Escreva na forma de porcentagem:

a) 1/8 . 25/25

= 25/200

= 12,5 / 100

= 12,5%

_______

b) 9/6 (:3)/(:3)

= 3/2 . 50/50

= 150/100

= 150%

________

c) 0,345=

= 345/1000

= 34,5/100

= 34,5%

------------------

3) Calcule:

a) 34% de 5%=

= 34/100 . 5/100

= 170/10000

= 17/1000

= 17. 10^(-3)

= 0,017

________

b) 75% de 44%=

= 75/100 . 44/100

= 3300/10000

= 33/100

= 0,33

____________

C)

c) 90% de 65%

= 90/100 . 65/100 (:5)/(:5)

= 9/10 . 13/20

= 117/200

= 0,585