a)
[tex]\left\{\begin{array}{l}-2x+5y=19 |\cdot 7\\7x-8y=-38|\cdot 2\end{array}\right.\\\\\underline{+\left\{\begin{array}{l}-14x+35y=133\\14x-16y=-76\end{array}\right.}\\\\-14x+14x+35y-16y=133-76\\19y=57 |:19\\\underline{y=3}\\\\-2x+15=19 |-15\\-2x=4 |:(-2)\\\underline{x=-2}\\\\\boxed{\left\{\begin{array}{l}x=-2\\y=3\end{array}\right.}[/tex]
b)
[tex]\left\{\begin{array}{l}-8x+9y=79|\cdot 2\\-5x-2y=-4|\cdot 9\end{array}\right.\\\\\underline{+\left\{\begin{array}{l}-16x+18y=158\\-45x-18y=-36\end{array}\right.}\\\\-16x-45x+18y-18y=158-36\\-61x=122 |:(-61)\\\underline{x=-2}\\\\10-2y=-4 |-10\\-2y=-14 |:(-2)\\\underline{y=7}\\\\\boxed{\left\{\begin{array}{l}x=-2\\y=7\end{array}\right.}[/tex]
Odpowiedź:
1.
- 2 x + 5 y = 19 / * 7
7 x - 8 y = - 38 / * 2
------------
- 14 x + 35 y = 133
14 x - 16 y = - 76
------------- dodajemy stronami
19 y = 57 / : 19
y = 3
------
- 2 x + 5*3 = 19
-2 x = 19 - 15
-2 x = 4 /: ( - 2)
x = - 2
Odp. x = - 2 , y = 3
====================
2.
- 8 x + 9 y = 79 / * 2
- 5 x -2 y = - 4 / * 9
-----------------
- 16 x + 18 y = 158
- 45 x - 18 y = - 36
- 61 x = 122 / : ( - 61 )
- 8* ( -2) + 9 y = 79
16 + 9 y = 79
9 y = 79 - 16
9 y = 63 / : 9
y = 7
Odp. x = - 2 , y = 7
Szczegółowe wyjaśnienie:
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Verified answer
a)
[tex]\left\{\begin{array}{l}-2x+5y=19 |\cdot 7\\7x-8y=-38|\cdot 2\end{array}\right.\\\\\underline{+\left\{\begin{array}{l}-14x+35y=133\\14x-16y=-76\end{array}\right.}\\\\-14x+14x+35y-16y=133-76\\19y=57 |:19\\\underline{y=3}\\\\-2x+15=19 |-15\\-2x=4 |:(-2)\\\underline{x=-2}\\\\\boxed{\left\{\begin{array}{l}x=-2\\y=3\end{array}\right.}[/tex]
b)
[tex]\left\{\begin{array}{l}-8x+9y=79|\cdot 2\\-5x-2y=-4|\cdot 9\end{array}\right.\\\\\underline{+\left\{\begin{array}{l}-16x+18y=158\\-45x-18y=-36\end{array}\right.}\\\\-16x-45x+18y-18y=158-36\\-61x=122 |:(-61)\\\underline{x=-2}\\\\10-2y=-4 |-10\\-2y=-14 |:(-2)\\\underline{y=7}\\\\\boxed{\left\{\begin{array}{l}x=-2\\y=7\end{array}\right.}[/tex]
Odpowiedź:
1.
- 2 x + 5 y = 19 / * 7
7 x - 8 y = - 38 / * 2
------------
- 14 x + 35 y = 133
14 x - 16 y = - 76
------------- dodajemy stronami
19 y = 57 / : 19
y = 3
------
- 2 x + 5*3 = 19
-2 x = 19 - 15
-2 x = 4 /: ( - 2)
x = - 2
Odp. x = - 2 , y = 3
====================
2.
- 8 x + 9 y = 79 / * 2
- 5 x -2 y = - 4 / * 9
-----------------
- 16 x + 18 y = 158
- 45 x - 18 y = - 36
------------- dodajemy stronami
- 61 x = 122 / : ( - 61 )
x = - 2
------------
- 8* ( -2) + 9 y = 79
16 + 9 y = 79
9 y = 79 - 16
9 y = 63 / : 9
y = 7
Odp. x = - 2 , y = 7
====================
Szczegółowe wyjaśnienie: