Ответы и объяснения

2013-05-22T09:56:37+04:00

2x+10=9-12-3y

21+6x+4y=8x+20

 

2x+3y=-13

-2x+4y=-1

 

7y=-14

x=-2

 

 

2x+3*(-2)=-13

2x=-13+6=-7

x=-3.5

Ответ: (-3.5;-2)

 

 

2013-05-22T09:59:58+04:00

2х+10=9-12-3у             2х+3у=9-12-10      2х+3у=-13      7у=-14     4*(-2)-2х=-1

21+6х+4у=8х+20         6х+4у-8х=20-21     4у-2х=-1          у=-2         -8-2х=-1

                                                                                                                   -2х= 7

                                                                                                                     х=-3,5

Ответ: х=-3,5;  у=-2