Question

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Resolva as equações, sendo U = Q.
a) x + 9 = 3
b) x – 12 = 15
c) x + 5 = - 4
d) 3x = -12
e) 3x = 10
f) 5x = 90
g) 3x – 7 = 2x + 5
h) 7x + 8 = 4x – 10
i) 4x – 15 = - 2x + 3
j) 2x – 4 – 8 = 4x
k) x + 2x – 1 – 3 = x

Answer 1

Resposta:

a) x + 9 = 3 -------> x = - 9 + 3 = -6

b) x – 12 = 15 -----> x = 12 + 15  -----> 27

c) x + 5 = - 4  -----> x = -5 -4  -----> - 9

d) 3x = -12  -----> x = - 12 / 3  -----> - 4

e) 3x = 10  ----->  x = 10 / 3  -----> 3,33...

f) 5x = 90   -----> x = 90 / 5  ----->  18

g) 3x – 7 = 2x + 5  ----->  3x - 2x = 7 + 5  -----> x = 12

h) 7x + 8 = 4x – 10  -----> 7x - 4x = - 8 - 10  ----->  3x = - 18  -----> x = - 18/3=-6

i) 4x – 15 = - 2x + 3  ----->  4x + 2x = 15 + 3  ----->  6x + 18  -----> x = 3

j) 2x – 4 – 8 = 4x  -----> - 12 = 4x - 2x  ----->  - 12 = 2x  -----> = - 6

k) x + 2x – 1 – 3 = x  -----> 3x - 1 - 3 = x  -----> 2x = - 4  -----> = -2