DAJE 20 PUNKTÓW
Rozwiąż równania:
a) 3x + 2(3x - 2) = 14
b) x/5-x/2=3
c) x-1/x=x/x-2


Odpowiedź :

Odpowiedź:

a)

3x+2(3x-2)=14

3x+6x-4=14

9x=18

x=2

b)

x/5-x/2=3

2x/10-5x/10=3

-3x/10=3

-3x=30

x= -3

c)

(x-1/)x = x/(x-2)

(x-1)/x-(x/(x-2)) = 0

(x-1)/x+(-1*x)/(x-2) = 0

((x-1)*(x-2))/(x*(x-2))+(-1*x^2)/(x*(x-2)) = 0

(x-1)*(x-2)-1*x^2 = 0

2-3*x = 0

(2-3*x)/(x*(x-2)) = 0

(2-3*x)/(x*(x-2)) = 0

2-3*x = 0

2-3*x = 0

-3*x = -2

x = -2/(-3)

x = 2/3

x = 2/3

Odpowiedź:

a)

3x + 2(3x - 2) = 14

3x + 6x - 4 = 14       | + 4

9x = 18    | : 2

x = 2

b)

x:5 - x:2 = 3

[tex]\frac{1}{5}[/tex] x - [tex]\frac{1}{2}[/tex]x = 3

[tex]\frac{2}{10}[/tex] x - [tex]\frac{5}{10}[/tex] x = 3    | *10

2x - 5x = 30

-3x = 30   | : -3

x = -10

c)

x - 1/x = x/x - 2   | * x

[tex]x^{2}[/tex] - 1 = x - 2x

[tex]x^{2}[/tex] + x = 1

w tym C nie wiem, coś takiego mi wychodzi