решить систему уравнений:{7x+3y=-1 и 3x-7y=17

7x + 3y = - 1 3x - 7y = 17 Решение 21х + 9y = - 3 - 21x + 49y = - 51 58y = - 54y = - 54/58 = - 27/29 3x - 7•( - 27/29 ) = 17 3x = 17 + ( 189/28 ) = 17 + 6,75 = 23,75 = 23 3/4 = 95/4 x = ( 95/4 ) : 3 = 95/12 = 7 8/12 = 7 2/3 Ответ ( 7 2/3 ; - 27/29 )