Question

precizează dacă ecuațiile din perechile următoare sunt echivalente

toate va rog plsss va dau coaraona plasss ​

Answer 1

Răspuns:

Explicație pas cu pas:

2

a) -x=7-21   si  x=14

-x=-14

x=14

- sunt echivalente

b) 3x-35=1  si  x=-12

3x=35+1

3x=36

x=36/3

x=12

- nu sunt echivalente

c) x:2=9  si  x=18

x=9×2

x=18

- sunt echivalente

d) -16:x=-2  si  x=-8

-2x=-16

x=-16/-2

x=8

- nu sunt echivalente

3

a) -4x=36

x=36/-4

x=-9

b) -4x=-15-1

-4x=-16

x=-16/-4

x=4

c) -6x=-8-4

-6x=-12

x=-12/-6

x=2

d) 5x=2-17

5x=-15

x=-15/5

x=-3

e) -3x=-5-4

-3x=-9

x=-9/-3

x=3

f) 5x-3x=11+3

2x=14

x=14/2

x=7

g) 4x-3x=15-13

x=2

h) 5x-5=2x+7

5x-2x=7+5

3x=12

x=12/3

x=4

i) 6x-15=6x-6-9

6x-6x=-15+15

0=0

j) 30-18x=20-20-15x

-18x+15x=-30

-3x=-30

x=-30/-3

x=10

k) 21x-28+19=15x-21

21x-9=15x-21

21x-15x=-21+9

6x=-12

x=-12/6

x=-2

l) x+3-4-8+x=11

2x-9=11

2x=11+9

2x=20

x=20/2

x=10

m) -6x+15+7x-9=-5x-18+6x+24

x+6=x+6

x-x=6-6

0=0

n) 1+{2[3+(4+x):5]-6}-7=8

1+{2[3+(4+x):5]-6}=8+7

1+{2[3+(4+x):5]-6}=15

{2[3+(4+x):5]-6}=15-1

{2[3+(4+x):5]-6}=14

2[3+(4+x):5]=14+6

2[3+(4+x):5]=20

[3+(4+x):5]=20:2

3+(4+x):5=10

3+(4+x)=10×5

3+(4+x)=50

4+x=50-3

4+x=47

x=47-4

x=43

4

a) 4x=12--16

4x=-4

x=-4/4

x=-1  nu este solutie din Z

b) 5x-31-6

5x=25

x=25/5

x=5   este solutie din N

c) 4x-12+9=5

4x-3=5

4x=5+3

4x=8

x=8/4

x=2  este solutie din N

d) 2x-6=3×2×4×5

2x-6=120

2x=120+6

2x=126

x=126/2

x=63   este solutie din N

Answer 2

Explicație pas cu pas:

2)

a) -x = 7 - 21 <=> -x = -14 => x = 14 (da)

b) 3x - 35 = 1 <=> 3x = 1 + 35 <=> 3x = 36 => x = 12 (nu)

c) x : 2 = 9 <=> x = 2×9 => x = 18 (da)

d) -16 : x = -2 <=> -16 = -2x => x = 8 (nu)

3)

a)

$- 4x - 36 = 0 \\ - 4x = 36 = > x = - 9$

b)

$- 4x + 1 = - 15 \\ - 4x = - 16 = > x = 4$

c)

$- 6x + 4 = - 8 \\ - 6x = - 12 = > x = 2$

d)

$5x + 17 = 2 \\ 5x = - 15 = > x = - 3$

e)

$- 3x + 4 = - 5 \\ - 3x = - 9 = > x = 3$

f)

$5x - 3 = 3x + 11 \\ 5x - 3x = 11 + 3 \\ 2x = 14 = > x = 7$

g)

$4x + 13 = 3x + 15 \\ 4x - 3x = 15 - 13 = > x = 2$

h)

$5(x - 1) = 2x + 7 < = > 5x - 5 = 2x + 7 \\ 5x - 2x = 7 + 5 < = > 3x = 12 \\ = > x = 4$

i)

$3(2x - 5) = 6(x - 1) - 9 \\ 6x - 15 = 6x - 6 - 9 \\ 6x - 6x = - 15 + 15 \\ 0x = 0 = > x\in \mathbb{Z}$

j)

$6(5 - 3x) = 20 - 5(4 + 3x) \\ 30 - 18x = 20 - 20 - 15x \\ - 18x + 15x = - 30 \\ - 3x = - 30 = > x = 10$

k)

$7(3x - 4) + 19 = 3(5x - 7) \\ 21x - 28 + 19 = 15x - 21 \\ 21x - 15x = - 21 + 9 \\ 6x = - 12 = > x = - 2$

l)

$((x + 3) - 4) - 8 + x = 11 \\ (x + 3 - 4) + x = 11 + 8 \\ x - 1 + x = 19 < = > 2x = 19 + 1 \\ 2x = 20 = > x = 10$

m)

$- 3(2x - 5) + 7x - 9 = - 5x - 2(9 - 3x) + 24 \\ - 6x + 15 + 7x - 9 = - 5x - 18 + 6x + 24 \\ x + 6 = x + 6 < = > 0x = 0 = > x\in \mathbb{Z}$

3)

a)

$4x + 16 = 12 < = > 4x = 12 - 16 \\ 4x = - 4 = > x = - 1 \not \in \mathbb{N}$

b)

$5x + 6 = 31 < = > 5x = 31 - 6 \\ 5x = 25 = > x = 5$

c)

$4(x - 3) + 9 = 5 < = > 4x - 12 + 9 = 5 \\ 4x - 3 = 5 < = > 4x = 8 \\ = > x = 2$

d)

$(((2x - 6) \div 5) \div 4) \div 2 = 3 \\ ((2x - 6) \div 5) \div 4 = 6 \\ (2x - 6) \div 5 = 24 \\ 2x - 6 = 120 < = > 2x = 126 \\ = > x = 63$