{3x + y = 11 {x = 12-2y 3(12-2y) +y = 11 36-6y+y = 11 -5y = -25 / : (-5) y = 5 x = 12 - 2*5 = 2 {x = 2 {y = 5 b) {4x - 2y = 7 / * 5 {3x + 5y = 1 / * 2 {20x - 10y = 35 {6x + 10y = 2 ----------------- 26x = 37 / : 26 x = 37/26 4*37/26 - 2y = 7 148/26 - 2y = 7 74/13 - 2y = 7 / * 13 74 - 26y = 91 26y = -17 / : 26 y = -17/26 {x = 37/26 {y = -17/26 Liczę na NAJ. :)
Metoda podstawiania {3x+y=11 {x+2y=12 {y=11-3x {x+2y=12 {y=11-3x {x+2(11-3x)=12 {y=11-3x {x+22-6x=12 {y=11-3x {-5x=12-22 {y=11-3x {-5x= -10 /:(-5) {y=11-3x {x=2 {y=11-3*2 {x=2 {y=5 {x=2 {x=2 {y=5 Metoda przeciwnych współczynników {4x-2y=7 /*(-3) {3x+5y=1 /*4 {-12x+6y= -21 +{12x+20y=4 26y= -17 /:26 y= -17/26 {4x-2y=7 {y= -17/26 {4x-2*(-17/26)=7 {y= -17/26 {4x+17/13=7 {y= -17/26 {4x=7-1 4/13 {y= -17/26 {4x=5 9/13 /:4 {y= -17/26 {x=74/13:4 {y= -17/26 {x=74/13*1/4 {y= -17/26 {x=37/26 {y= -17/26 {x=1 11/26 {y= -17/26
