Question

Determinați valoarea numărului natural x, astfel încat.
a) 2x + 4x = 18;
b) 3x - x = 26;
c) 5x + 3 = 33;
d) 6x = 2x + 24;
e) 4x + 9 = x + 12;
f) 8x - 3 = 2x + 30.​

Answer 1

a) 2x + 4x = 18;

6x= 18

x= 18/6

x= 3

b) 3x - x = 26;

2x= 26

x= 26/2

x= 13

c) 5x + 3 = 33;

5x= 33-3

5x= 30

x= 30/5

x= 6

d) 6x = 2x + 24;

6x-2x= 24

4x= 24

x= 24/4

x= 6

e) 4x + 9 = x + 12;

4x-x= 12-9

3x= 3

x= 3/3

x= 1

f) 8x - 3 = 2x + 30.

8x-2x= 30+3

6x= 33

x= 33/6

x= 5,5

Answer 2

Răspuns:

Explicație pas cu pas:

a)   2 x + 4 x = 18

     6 x = 18

         x = 18 : 6

         x = 3 ∈ N

_______________________

b)

3 x - x = 26

2 x = 26

x = 26 : 2

x = 13 ∈ N

________________

c)

5 x + 3 = 33

5 x = 33 - 3

5 x = 30

x = 30 : 5

x = 6 ∈ N

_______________

d)

6 x = 2 x + 24

6 x - 2 x = 24

4 x = 24

x = 24 : 4

x = 6

________________

e)

4 x + 9 = x + 12

4 x - x = 12 - 9

3 x = 3

x = 3 : 3

x = 1 ∈ N

_______________

f)

8 x - 3 = 2 x + 30

8 x - 2 x = 30 + 3

6 x = 33

x = 33 : 6

x = 5,5 ∉ N

Daca in loc de 30 este 33, atunci solutia ecuatiei este:

8 x - 3 = 2 x + 33

8 x - 2 x = 33 + 3

6 x = 36

x = 36 : 6

x = 6 ∈ N