Question

rezolvati in multimea numerelor intregi ecuatiile:
a) 2x+5=x+6
b) 2x+12=x-6
c) 3x-1=x+9
d) 4x+9=3x+17
e) 2x-5=x+7
f) 4x-12=x+6
g) 2x+9=7+x
h) 4-3x=x+12
i) -x+7=x+21
j) 3-2x=-x+6
k) 6+3x=-54+x
l) 1+9x=-89-x​

Answer 1

Răspuns:

Explicație pas cu pas:

a)

2x + 5 = x + 6

2 x - x = 6 - 5

x = 1 ∈ Z

___________

b)

2 x + 12 = x - 6

2 x - x = - 6 - 12

x = - 18 ∈ Z

_____________

c)

3 x - 1 = x + 9

3 x - x = 9 + 1

2 x = 10

x = 10 : 2

x = 5

_____________

d)

4 x + 9 = 3 x + 17

4 x - 3 x = 17 - 9

x = 8

_____________

e)

2 x - 5 = x + 7

2 x - x = 7 + 5

x = 12

____________

f)

4 x - 12 = x + 6

4 x - x = 6 + 12

3 x = 18

x = 18 : 3

x = 6

___________

g)

2 x + 9 = 7 + x

2 x - x = 7 - 9

x = - 2

____________

h)

4 - 3 x = x + 12

- 3 x - x = 12 - 4

- 4 x = 8

x = - 2

_______________

i)

- x + 7 = x + 21

- x - x = 21 - 7

- 2 x = 14

x = - 7

____________

j)

3 - 2 x = -x + 6

- 2 x + x = 6 - 3

- x = 3

x = - 3

____________

k)

6 + 3 x = - 54 + x

3 x - x = - 54 - 6

2 x = - 60

x = ( - 60) : 2

x = - 30

___________

l)

1 + 9 x = - 89 - x

9 x + x = - 89 - 1

10 x = - 90

x = ( - 90 ) : 10

x = - 9 ​