prosze o szybka odpowiedz daje naj za wszystkie zadania rozwiąz metoda podstawiania {x=5 {3x+y=17 b {x+3y=13 {y=4x c) {x=y+3 {x+2y=9 d) {5x-2y=29 {y=x-4 e) {x+2y=3 {2x+5y=5 rozwiąz metoda przeciwnych współczynników (zastosuj do wyznacze

zad. 1 met. podstawiania: a) {x = 5 {3x + y = 17 {x = 5 {3 * 5 + y = 17 =>15 + y = 17                              y = 2 {x = 5 {y = 2 b) {x + 3y = 13 {y = 4x {x + 3 * 4x = 13 =>13x = 13 /:13 {y = 4x                   x = 1 {x = 1 {y = 4 * 1 {x = 1 {y = 4 c) {x = y + 3 {x + 2y = 9 {x = y + 3 {y + 3 + 2y = 9 => 3y = 6 /:3                              y = 2 {x = 2 + 3 {y = 2 {x = 5 {y = 2 d) {5x - 2y = 29 {y = x - 4 {5x - 2 * (x - 4) = 29 => 5x - 2x + 8 = 29 {y = x - 4                       3x = 21 /:3                                      x = 7 {x = 7 {y = 7 - 4 {x = 7 {y = 3 e) {x + 2y = 3 => x = 3 - 2y {2x + 5y = 5 {x = 3 - 2y {2(3 - 2y) + 5y = 5 => 6 - 4y + 5y = 5                                    y = -1 {x = 3 - 2 * (-1) {y = -1 {x = 5 {y = -1 zad. 2 met. przeciwnych współczynników a) {-2x + y = 4 {2x + 2y = 2 => 2x + 2 * 2 = 2 __________     2x = -2 /:2 3y = 6    /:3       x = -1 y = 2 {x = -1 {y = 2 b)  {2x - y = 4   / * 2 {x + 2y = 7 {4x - 2y = 8 {x + 2y = 7 =>   3 + 2y = 7 ___________   2y = 4 /:2 5x = 15   /:5      y = 2 x = 3 {x = 3 {y = 2 zad. 3 (met. podstawiania) {2(x + y) - 3y = 2x + 1 {4x - 3(x + 2y) = 7 - 4y {2x + 2y - 3y = 2x + 1 {4x - 3x - 6y = 7 - 4y {-y = 1 {x - 2y = 7 {y = -1 {x - 2y = 7 {y = -1 {x - 2 * (-1) = 7 => x + 2 = 7                              x = 5 {y = -1 {x = 5