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2x-5y+3=10
-2/3x+14=25-7y

Odpowiedź :

Agaviz

[tex]\left\{ \begin{array}{ll}2x-5y+3=10\\-\dfrac{2}{3}x+14=25-7y}\end{array} \right.[/tex]

[tex]\left\{ \begin{array}{ll}2x-5y=10-3\\-\dfrac{2}{3}x+7y=25-14}\end{array} \right.[/tex]

[tex]\left\{ \begin{array}{ll}2x-5y=7\\-\dfrac{2}{3}x+7y=11 \ \ \ \ \ |\cdot3}\end{array} \right.[/tex]

[tex]\left\{ \begin{array}{ll}2x-5y=7\\-2x+21y=33}\ \ \ \ \ \ \ \ (+)\end{array} \right.\\-------------[/tex]

[tex]2x+(-2x)-5y+21y=7+33[/tex]

[tex]2x-2x+16y=40[/tex]

[tex]16y=40\ \ \ \ \ |:8[/tex]

[tex]2y=5\ \ \ \ \ |:2[/tex]

[tex]y=2,5[/tex]

[tex]\left\{ \begin{array}{ll}y=2,5\\2x-5y=7}\end{array} \right.[/tex]

[tex]\left\{ \begin{array}{ll}y=2,5\\2x-5\cdot2,5=7}\end{array} \right.[/tex]

[tex]\left\{ \begin{array}{ll}y=2,5\\2x-12,5=7}\end{array} \right.[/tex]

[tex]\left\{ \begin{array}{ll}y=2,5\\2x=7+12,5}\end{array} \right.[/tex]

[tex]\left\{ \begin{array}{ll}y=2,5\\2x=19,5\ \ \ \ \ |:2}\end{array} \right.[/tex]

[tex]\left\{ \begin{array}{ll}x=9,75\\y=2,5}\end{array} \right.[/tex]

Bartek4877viz

Odpowiedź:

{ x = 9,75

{y = 2,5

Szczegółowe wyjaśnienie:

{ 2x - 5y + 3= 10

{- ⅔ x + 14 = 25 - 7y

{ 2x - 5y = 10 - 3

{ -⅔x + 7y = 25 - 14

{2x - 5y = 7

{ - ⅔ x + 7y = 11 /*3

{2x - 5y = 7

{ - 2x + 21y = 33

{ 2x - 5y - 2x + 21y = 7 + 33

- 5y + 21y = 40

16y = 40 /:16

y = 2,5

{2x - 5y = 7

2x - 5 * 2,5 = 7

2x - 12,5 = 7

2x = 7 + 12,5

2x = 19,5 /:2

x = 9,75

{ x = 9,75

{y = 2,5

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