1){х + у = 12{х - у = - 6метод сложения:x + y + x - y = 12 + (-6)2х=6х=33+у=12у= 12-9у= 9ответ: (3 ; 9 )2){х +у = 55{x - y = -25x+y +x- y = 55 + (-25)2x = 30x= 1515 + y = 55y= 55-15y=40ответ: (15 ; 40)3) {x+y = -13{x - y = - 1x+y +x-y = -13 + (-1)2x = -14x= -14/2x= -7-7 +y = -13y= - 13 + 7y= -6ответ: (-7 ; - 6)4) {x+y = 3{x - y = -13x+y+x-y = 3 + (-13)2x=-10x= -10 /2x= -5-5+ y = 3y= 3+5y=8ответ: ( - 5 ; 8)5){ x + y = 10{x - y = - 5.84x + y + x - y = 10 + (-5.84)2x = 4.16x= 4.16 / 2x =2.082.08 + y = 10y = 10 - 2.08y = 7.92ответ : (2,08 ; 7,92 )6) {x + y = 5/56{ x - y = - 1/168x + y + x - y = 5/56 - 1/1682x = 15/168 - 1/1682x = 14/1682x = 7/84x= 7/84 : 2 = 7/84 * 1/2х= 7/1687/168 + у = 5/56у= 5/56 - 7/168 = 15/168 - 7/168 у= 8/168у= 1/21ответ : ( 7/168 ; 1/21)