Question

meto de reduccion
respuesta paso a paso a) x-4y=2 b) 2x+2y=6
2x-5y=7 3x+4y=12

Answer 1

MÉTODO DE REDUCCIÓN.

1) x - 4y = 2       (2)
2) 2x + 2y = 6    (4)

2x - 8y = 4
8x + 8y = 24
-------------------
10x + 0y = 28

10x = 28
x = 28/10
x = 14/5

Reemplazo x en 2

2x + 2y = 6
2 (14/5) + 2y = 6
28/5 + 2y = 6
2y = 6 - 28/5
2y = (6 * 5 - 28)/5
2y = (30 - 28)5
2y = 2/5
y = 2/5/2
y = 2/10
y = 1/5

Solución : 

x = 14/5
y = 1/5
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1) 2x - 5y = 7      (3)
2) 3x + 4y = 12   (-2)

6x - 15y = 21
- 6x - 8y = - 24
--------------------
0x - 23y = - 3

- 23y = - 3
y = 3/23

Sustituyo y en 2

3x + 4y = 12
3x + 4 (3/23) = 12
3x + 12/23 = 12
3x = 12 - 12/23
3x = (12 * 23 - 12)/23
3x = (276 - 12)/23
3x = 264/23
x = 264/23/3/1
x = 264/69
x = 88/23

Solución : 

x = 88/23
y = 3/23

Answer 2

x - 4y =  2  ...... I
2x+2y = 6  ...... II    por (2)

x - 4y = 2
4x+4y = 12
''''''''''''''''''''''''''
5x      = 14

$x= \frac{14}{5}$  .....  III

III en I

x-4y = 2

$\frac{14}{5}-4y = 2$

$\frac{14}{5} -2 = 4y$

$\frac{14-10}{5} = 4y$

$\frac{4}{20} = y$

$\frac{1}{5} = y$

CS = (14/5; 1/5)