Question

Scrie-mi repede 20 ecuati in z rezolvate dau
coroana

Answer 1

Răspuns:

a) 7x +14 = 0

7x = -14

x = (-14) : 7

x = -2

-2 ∈ Z,

b) x : (-7) = 21

x = 21 * (-7)

x = -147

c) 5 : x = -25

5 = (-25) * x

5 : (-25) = x

1 : (-5) = x

-0.2 = x

-0.2 ∉ Z

d) 14x + 16 = -2x

14 x + 2x + 16 = 0

16 x + 16 = 0

16 x = -16

x = (-16) : 16

x = -1 ∈ Z

e) 7x - 19 = 3x - 143

7x - 3x - 19 = -143

4x - 19 = -143

4x = -143 + 19

4x = -124

x = (-124) : 4

x = -31 ∈ Z

f) 7 (x - 3) = -42

(x - 3) = (-42) : 7

x - 3 = -6

x = (-6) + 3

x = (-3)

(-3) ∈ Z

g) 5 (-x + 2) = -4 (2x - 4)

-5x + 10 = -8x + 16

-5x + 8x = 16 - 10

3x = 6

x = 6 : 3

x = 2 ∈ Z

h) 6x +36 = 0

x=36;6

x=6

i) 5(x+4) = 4x

5x+20=4x

5x-4x=-20

x=20

j)5x+25=0

5x=-25

x=-25;5

x=-5

Explicație pas cu pas: