y=5-2x 4x-(5-2x)=10 4x-5+2x=10 6x=15 /:6 x=15/6 y=5-2*15/6 y=0 y=-4-2x x-2(-4-2x)=7 x+8+4x=7 5x=15 /:5 x=3 y=-4-2*3 y=-10 1/2x+3y=11 /*2 x=22-6y 1/4x-2=-5 /*4 x-8=-20 22-6y-8=-20 -6y=-36 /:-6 y=6 x=22-6*6 x=-14 1/2x+1/4y=-2 /*4 2x+y=-8 y=-8-2x 5x-3y=2 5x-3*(-8-2x)=2 5x+24+6x=2 11x=-22 /:11 x=-2 y=-8-2*(-2) y=-4
1. 2x + y = 5 4x - y = 10 y = 5 - 2x 4x - 5 - 2x = 10 2x = 15 |: 2 x = 7,5 y = 5 - 2 * 7,5 y = 5 - 15 y = -10 x = 7,5 y = -10 2. 2x - y = -4 x - 2y = 7 x = 7 + 2y 2(7 + 2y) - y = -4 14 + 4y - y = -4 3y = -18 |:3 y = -6 x = 7 + 2 * - 6 x = 7 + 12 x = 19 x = 19 y = -6 3. ½x + 3y = 11 ¼x - 2 = -5 ¼x = -5 + 2 ¼x = -3 |: ¼ x = -3 * 4 x = -12 ½ * -12 + 3y = 11 -6 + 3y = 11 3y = 11 + 6 3y = 17 |:3 y = 5⅔ x = -12 y = 5⅔ 4. ½x + ¼y = -2 |*4 2x + y = -8 y = -8 - 2x 5x - 3y = 2 5x - 3 * ( -8 - 2x ) = 2 5x + 24 + 6x = 2 11x = -22 |:11 x = -2 y = -8 - 2*(-2) y = -4 (przykład 4 i 5 są takie same)
Rozwiązanie w załączniku ;))
