3x-7y=0 5(x-2)+3y+6)=1用代入法解,急用,3x-7y=0 5(x-2)+3(y+6)=1不好意思括号打错了.求X=y=

3x = 7y (1),
5x + 3y = -7 (2)
(1)式乘以5,(2)式乘以3,得
15x = 35y (3),
15x + 9y = -21 (4)
将(3)代入(4),得
35y + 9y = 44y = -21,解得 y = -21/44
将 y=-21/44 代入(1),解得 x = -49/44
（验证略）所以,x=-49/44 y=-21/44