rozwiázywanie rownan metada podstawiania (to takie jedno, dlugie rownanie) 3x+4y=2 5x+7y=1 plis pomozcie ;**

3x+4y=2 5x+7y=1 3x=2-4y /3 5x+7y=1 x= 2/3 - (4y)/3 5 [2/3 - (4y)/3] + 7y=1 x= 2/3 - (4y)/3 10/3 - (20y)/3 +7y=1 /*3 x= 2/3 - (4y)/3 /*3 10 - 20y + 21y = 3 x= 2/3 - (4y)/3 y= -7 3x= 2- 4 *(-7) y= -7 3x= 30 /3 y=-7 x=10 y=-7

3x+4y=2 // -4y 5x+7y=1 3x= 2- 4y // ÷ 3 5x+7y=1 x = 2/3 - 4/3y 5(2/3 - 4/3y)+7y=1 10/3 - 20/3y + 7y = 1 // - 10/3 - ⅓y = - 7/3 // ÷ (-⅓ ) y = 7 x= 2/3 - 9⅓ x= 8 2/3