Question

1) Calcule o valor de x nas proporções abaixo:

A) x/8=5/4

B) x/7=3/7

C) 4/x=5/10

D) 3/x=6/8

E)7/6=42/x

F) 3/7=60/x

2) Resolva os equações sendo U=Q.

A) 4×+8=2×-6

B) 3×+9=2×-5

C) 7×+4=2×-21

D) 4(×+3)=2(×-3)

E) ×/2+×/3=5
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Answer 1

Explicação passo-a-passo:

A) x/8=5/4

4.x=8.5

4x=40

x=40/4

x=10

B) x/7=3/7

7.x=3.7

7x=21

x=21/7

x=3

C) 4/x=5/10

5.x=4.10

5x=40

x= 40/5

x= 8

D) 3/x=6/8

6.x=8.3

6x=24

x=24/6

x= 4

E)7/6=42/x

7.x=6.42

7x=252

x=252/7

x=36

F) 3/7=60/x

3.x= 7.60

3x=420

x=420/3

x=140

(2)

A) 4×+8=2×-6

4x-2x=-6-8

2x= -14

x=-14/2

x=-7

B) 3×+9=2×-5

3x-2x=-5-9

x= -14

C) 7×+4=2×-21

7x-2x=-21-4

5x=-25

x=-25/5

x=-5

D) 4(×+3)=2(×-3)

4x+12=2x-6

4x-2x=-6-12

3x=-18

x=-18/3

x=-6

E) ×/2+×/3=5

(2x+3x)/6=5

5x/6=5

5x=5.6

5x=30

x=30/5

x=6