Question

resolva cada sistema de equaçoes pelo metodo que julgar melhor sendo dado ajuda!

Answer 1

Método da adição

a)2x=6 y=3
x=3

b)3x=6 y=-1/3
x=2

c)4x=12 y=9
x=3

d)2y=10 x=2
y=5

e)2x=36 y=2
x=18

f) (-3)a segunda equação
7y=7 x=0
y=1

g)6x=6 y=2
x=1

h) Método da substituição
y-2y=1 x=-2
y=-1

i)2x=6
x=3

j) (-2)a segunda equação
-7x=-14 y=1
x=2

k)6x=-6 y=0
x=-1

l)(-1) a primeira equação
4x=-8 y=2
x=-2

Answer 2

Resposta:

Eu irei usar o método de substituição em todas.

a)

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x + y = 6

x - y = 0

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x = 6 - y

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6 - y - y = 0

-2y = -6

y = -6/-2 = 3

---

x  = 6 - 3 = 3

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b)

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x + 3y = 1

2x - 3y = 5

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x = 1 - 3y

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2.(1 - 3y) - 3y = 5

2 - 6y - 3y = 5

-9 y = 3

y = 3/-9 = -1/3

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x = 1 - 3.(-1/3)

x = 1 + 3/3 = 1 + 1 = 2

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c)

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3x - y = 0

x + y = 12

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x = 12 - y

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3.(12 - y) - y = 0

36 - 3y - y = 0

-4y = -36

y = -36/-4 = 9

---

x = 12 - 9 = 3

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d)

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y - x = 3

y + x = 7

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y = 3 + x

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3 + x + x = 7

2x = 4

x = 4/2 = 2

---

y = 3 + 2 = 5

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e)

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x + y = 20

x - y = 16

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x = 20 - y

---

20 - y - y = 16

-2y = -4

y = -4/-2 = 2

---

x = 20 - 2 = 18

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f)

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3x + y = 1

x - 2y = -2

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y = 1 - 3x

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x - 2.(1 - 3x) = -2

x - 2 + 6x = -2

7x = 0

x = 0/7 = 0

---

y  = 1 - 3.0 = 1

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g)

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4x + y = 6

2x - y = 0

---

y = 6 - 4x

---

2x - 6 + 4x = 0

6x = 6

x = 6/6 = 1

---

y = 6 - 4.1 = 2

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h)

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x = 2y

y - x = 1

---

y - 2y = 1

-y = 1

y = -1

---

x = 2.(-1) = -2

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i )

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x + y = 2

x - y = 4

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x = 2 - y

---

2 - y - y = 4

- 2y = 2

y = 2/-2 = -1

---

x = 2 - (-1) = 3

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j )

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x - 2y = 0

4x - y = 7

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x = 2y

---

4.(2y) - y = 7

8y - y = 7

y = 7/7 = 1

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x = 2.1 = 2

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k )

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5x + y = -5

x - y = -1

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y = -5 - 5x

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x +5 + 5x = -1

6x = -6

x = -6/6 = -1

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y = -5 -5.(-1)

y = -5 + 5 = 0

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l )

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x + y = 0

5x + y = -8

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x = -y

---

5.(-y)+y = -8

-5y + y = -8

y = -8/-4 = 2

---

x = - 2

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