3x-5y=-1解方程组 ｛2x=3y
令x = 3k y =2k
代入 得
9k - 10k =-1
k=1
x= 3 y =2｛a|4+b|4=2｛a|6+b|3=2｛3（a-3）=b-1｛5（b-1）=3（a+5)这两道会吗？专家｛a|4+b|4=2a+b = 8｛a|6+b|3=2a+2b = 12b= 4a =4｛3（a-3）=b-13a-9 =b-1 3a = b+8｛5（b-1）=3（a+5)5b-5 = 3a + 155b= 3a+20b+8=5b-204b = 28b=7a = 5别来了啊哦谢谢·~~~~