Question

1- Escreva, 5 Pares ordenados que sejam soluções de cada uma das equações:
(passo a passo prfvr)

a) x+y=8

b) x+2y=20

c) x-y=5

d) x\2 + y=4

e) 5x+y=20

f) x+ y\3=1

g) 2x+2y=10

h) y= x\5

Answer 1

a)
x + y = 8
x = 0
0 + y = 8
y = 8
(0,8)
===================================
x = 1
1 + y = 8
y = 8 - 1
y = 7
(1,7)
==============================
x = 2
2 + y = 8
y = 8 - 2
y = 6
(2,6)
=================================
x = 3
x + y = 8
3 + y = 8
y = 8 - 3
y = 5
(3,5)
=============================
x = 4
x + y = 8
4 + y = 8
y = 8 - 4
y = 4
(4,4)
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b)
x = 0
x+2y=20
0 + 2y = 20
2y = 20
y = 20/2
y = 10
---------------------------------------
x = 2
x + 2y = 20
2 + 2y = 20
2y = 20 - 2
2y = 18
y = 18/2
y = 9
----------------------------------------------
x = 4
x+2y=20
4 + 2y = 20
2y = 20 - 4
2y = 16
y = 16/2
y = 8
-------------------------------------------------
x = 6
x + 2y = 20
6 + 2y = 20
2y = 20 - 6
2y = 14
y = 14/2
y = 7
-----------------------------------------------
x = 8
x+2y=20
8 + 2y = 20
2y = 20 - 8
2y = 12
y = 12/2
y = 6
-------------------------------------------
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c)
x = 0
x-y=5
0 - y = 5 ( - 1)
y = - 5
---------------------------------------
x = 1
x-y=5
1 - y = 5
1 - 5 = y
- 4 = y
y = - 4
--------------------------------------
x = 2
x - y = 5
2 - y = 5
2 - 5 = y
- 3 = y
y = - 3
-------------------------------
x = - 1
x - y = 5
- 1 - y = 5
- 1 - 5 = y
- 6 = y
y = - 6
--------------------------------------------
x = 5
x-y=5
5 - y = 5
5 - 5 = y
0 = y
y = 0
----------------------------------------
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d) x\2 + y=4
x = 0
0/2 + y = 4
y = 4
------------------------
x = 2
x\2 + y=4
2/2 + y = 4
4 + y = 4
y = 4 - 4
y = 0
----------------------------------
x = 4
x\2 + y=4
4/2 + y = 4
2 + y = 4
y = 4 - 2
y = 2
-------------------------------------
x = 6
x\2 + y=4
6/2 + y = 4
3 + y = 4
y = 4 - 3
y = 1
-----------------------------
x = 8
x\2 + y=4
8/2 + y = 4
4 + y = 4
y = 4 - 4
y = 0
-------------------------
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e) 5x+y=20
x = 0
5.0 + y = 20
y = 20
---------------------------------
x = 1
5x+y=20
5.1 + y = 20
5 + y = 20
y = 20 - 5
y = 15
----------------------------------------
x = 2
5x+y=20
5.2 + y = 20
10 + y = 20
y = 20 - 10
y = 10
-------------------------------------------------
x = 3
5x+y=20
5.3 + y = 20
15 + y = 20
y = 20 - 15
y = 5
--------------------------------------------------
x = 4
5x+y=20
5.4 + y = 20
20 + y = 20
y = 20 - 20
y = 0
------------------------------------------------
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f) x + y\3=1

x = 0
y = 1
3
y = 3.1
y = 3
-----------------------------------
x = 1
x + y\3=1
1 + y/3 = 1
y = 1 - 1  
3
y = 0
3
y = 0
 ------------------------------
x = 2
x + y\3=1
2 + y  =  1
      3
y = 1 - 2
3
y = - 1
3
y = - 3
----------------------------------
x = 3
x + y\3=1
3 + y  =  1
      3
y = 1 - 3
3

y = - 2
3
y = - 6
--------------------------------
x = 4
x + y\3=1
4 + y  =  1
      3
y = 1 - 4
3
y = - 3
3
y = - 9
-------------------------------------------
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g)
x = 0
2x+2y=10
2.0 + 2y = 10
2y = 10
y = 10/2
y = 5
--------------------------------
x = 1
2x+2y=10
2.1 + 2y = 10
2 + 2y = 10
2y = 10 - 2
2y = 8
y = 8/2
y = 4
-------------------------------
x = 2
2x+2y=10
2.2 + 2y = 10
4 + 2y = 10
2y = 10 - 4
2y = 6
y = 6/2
y = 3
-------------------------------
x = 3
2x+2y=10
2.3 + 2y = 10
6 + 2y = 10
2y = 10 - 6
2y = 4
y = 4/2
y = 2
----------------------------
x = 4
2x+2y=10
2.4 + 2y = 10
8 + 2y = 10
2y = 10 - 8
2y = 2
y = 2/2
y = 1
-----------------------------------------------------------------------
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h) y= x\5

x = 1
y = 1
      5
----------------
x = 2
y = 2
      5
-----------------
x = 3
y = 3
      5
---------------
x = 4
y = 4
      5
--------------
x = 0
y = 0
      5
y = 0