[tex]( 3x+ 4y -5)^{2} +( -x-2y +1)^{2} = 0\\9x^{2} + 12xy- 15x+ 12xy+ 16y^{2} -20y- 15x- 20y +25=\\9x^{2}+16y^{2} + 24xy- 30x- 40y[/tex]
jeden nawias na raz jakby co
[tex]( -x-2y+1)^{2} = x^{2} + 2xy-x + 2xy+ 4y^{2} -2y-x-2y+1=\\x^{2}+ 4y^{2} + 4xy - 2x -4y+ 1[/tex]
[tex]9x^{2}+16y^{2} + 24xy- 30x- 40y + x^{2}+ 4y^{2} + 4xy - 2x -4y+ 1 = 0\\10x^{2} + 20y^{2} + 28xy -32x - 44y + 1= 0\\\\10x( x+ 2) + 4( 7y+ 8) - ( 44y-1 ) = 0\\10x= 0 x= 0 \\x+2= 0\\x= -2\\7y+8 = 0\\7y = 8/7\\44y-1 = 0\\y = 1/44[/tex]
