Toán CHo x=by+cz;y=ax+cz;z=ax+by. CMR : P=1/a+1 + 1/b+1 + 1/c+1 = 2 17/11/2021 By Arya CHo x=by+cz;y=ax+cz;z=ax+by. CMR : P=1/a+1 + 1/b+1 + 1/c+1 = 2
Đáp án: x+y+z=by+cz+ax+by+ax+cz =2(ax+by+cz) =2(ax+x) =2x(a+1) =>a+1=x+y+z/2x tượng tự b+1=x+y+z/2y c+1=x+y+z/2z rồi bạn thay vào tính nha Trả lời
Ta có : `P=1/(a+1)+1/(b+1)+1/(c+1)` `=>P=x/[(a+1)x]+y/[(b+1)y]+z/[(c+1)z]` `=>P=[by+cz]/[ax+x]+[ax+cz]/[by+y]+[ax+by]/[cz+z]` `=>P=[by+cz]/[ax+by+cz]+[ax+cz]/[by+ax+cz]+[ax+by]/[cz+ax+by]` `=>P=[2(ax+by+cz)]/[ax+by+cz]=2` `=>ĐPCM` Trả lời
Đáp án:
x+y+z=by+cz+ax+by+ax+cz
=2(ax+by+cz)
=2(ax+x)
=2x(a+1)
=>a+1=x+y+z/2x
tượng tự
b+1=x+y+z/2y
c+1=x+y+z/2z
rồi bạn thay vào tính nha
Ta có :
`P=1/(a+1)+1/(b+1)+1/(c+1)`
`=>P=x/[(a+1)x]+y/[(b+1)y]+z/[(c+1)z]`
`=>P=[by+cz]/[ax+x]+[ax+cz]/[by+y]+[ax+by]/[cz+z]`
`=>P=[by+cz]/[ax+by+cz]+[ax+cz]/[by+ax+cz]+[ax+by]/[cz+ax+by]`
`=>P=[2(ax+by+cz)]/[ax+by+cz]=2`
`=>ĐPCM`