Question

equações me ajude a resolver 1) 7 y + 5 - y + 8 = 31 2) 5 . (3 - 2 a) = 55 3) 27 = 3 . (x + 3) 4) 16 x + 2 . (7 x + 8) - 9 = 67 5) 6 . (4 z + 2) + 7 . ( - 5 z + 3) = 66 6) 12 + (3 x + 6) . (- 7) - 5 = 70

Answer 1

1)
7 y + 5 - y + 8 = 31 
7y - y + 5 + 8 = 31
6y + 13 = 31
6y = 31 - 13
6y = 18
y = 18/6
y = 3
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2)
5 . (3 - 2 a) = 55 
15 - 10a = 55
15 - 55 = 10a 
- 40 = 10a
- 40/10 = a
- 4 = a
a = - 4
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3) 
27 = 3 . (x + 3) 
27 = 3x + 9
27 - 9 = 3x
18 = 3x
18/3 = x
6 = x
x = 6
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4) 
16 x + 2 . (7 x + 8) - 9 = 67 
16x + 14x + 16 - 9 = 67
30x + 7 = 67
30x = 67 - 7
30x = 60
x = 60/30
x = 2
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5) 

6.(4 z + 2) + 7.( -5 z + 3) = 66 
24z + 12 - 35z + 21 = 66
24z - 35z + 33 = 66
- 11z = 66 - 33
- 11z = 33
11z = - 33
z = - 33/11
z = - 3
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6)
12 + (3 x + 6) . (- 7) - 5 = 70
12 - 21x - 42 - 5 = 70
12 - 21x - 47 = 70
12 - 47 - 21x = 70
- 35 - 21x = 70
- 35 - 70 = 21x
- 105 = 21x
21x = - 105
x = -105/21
x = - 5