问题标题：
【Thereare60birdinthetrees,Afterawhile,4birdsflytothesecondtreefromthefirsttreeand7birdsflytothirdtreetreefromthesecondtree.Thenthereare20biedsineverytree.DOyouknowhowmanybiedsareineverytreeatfirst?】
问题描述：
Thereare60birdinthetrees,Afterawhile,4birdsflytothesecondtreefromthefirsttreeand7birdsflytothirdtreetreefromthesecondtree.Thenthereare20biedsineverytree.DOyouknowhowmanybiedsareineverytreeatfirst?
马超飞回答：
x+y+z=60
x-4=20
y+4-7=20
z+7=20
x24
y23
z13
点击显示
英语推荐
热门英语推荐