已知(3a-b)/(2b-a)=7,(x+y)/(2x-y)=5,求(3ax-by)/(ax+2by)快

来源:学生作业帮助网 编辑:六六作业网 时间:2024/12/25 13:48:10
已知(3a-b)/(2b-a)=7,(x+y)/(2x-y)=5,求(3ax-by)/(ax+2by)快已知(3a-b)/(2b-a)=7,(x+y)/(2x-y)=5,求(3ax-by)/(ax+2

已知(3a-b)/(2b-a)=7,(x+y)/(2x-y)=5,求(3ax-by)/(ax+2by)快
已知(3a-b)/(2b-a)=7,(x+y)/(2x-y)=5,求(3ax-by)/(ax+2by)

已知(3a-b)/(2b-a)=7,(x+y)/(2x-y)=5,求(3ax-by)/(ax+2by)快
(3a-b)/(2b-a)=7,
3a-b=7(2b-a),
2a=3b
(ax+y)/(2x-y)=5,
x+y=5(2x-y),
3x=2y
(3ax-by)/(ax+2by),通过分子和分母同乘以6,
=6(3ax-by)/6(ax+2by)
=(18ax-6by)/(6ax+12by)
=(3*2a*3x-6by)/(2a*3x+12by)
=(3*3b*2y-6by)/(3b*2y+12by)
=(18by-6by)/(6by+12by)
=12by/18by
=2/3
或(3a-b)/(2b-a)=7,
3a-b=7(2b-a),
2a=3b.1
(ax+y)/(2x-y)=5,
x+y=5(2x-y),
3x=2y.2
1式*2式得
6ax=6by
ax=by
(3ax-by)/(ax+2by)
=(3by-by)/(by+2by)
=2by/3by
=2/3