x+y+z=142 x/28+y/30+z/35=4.5 z/28+y/30+x/35=4.7 怎么解.

来源：学生作业帮编辑：作业帮分类：数学作业时间：2024/05/08 12:07:32

(z/28+y/30+x/35)-(x/28+y/30+z/35)=(1/28-1/35)(z-x)=(z-x)/140=0.2
z-x=28
(z/28+y/30+x/35)+(x/28+y/30+z/35)=(1/28+1/35)(x+z)+y/15
=9/140*(2x+28))+y/15=9x/70+y/15+1.8=9.2
9x/70+y/15=9.2-1.8=7.4
27x+14y=1554
y=(1554-27x)/14=111-27x/14
x+y+z=x+111-27x/14+x+28=x/14+139=142
x=42
y=30
z=70

x/30+y/28+z/35=4.5 x/30+y/35+z/28=4.7 x+y+z=142 这个方程怎么解? x+y+z=142 x/28+y/30+z/35=4.5 z/28+y/30+x/35=4.7 怎么解. 解三元一次方程组1.x+y+z=142 30/x+28/y+35/z=4.5 30/x+35/y+28/z=4.7 28\x+30\z+35\y=4.5 28\y+30\z+35\x=4.3 x+y+z=142 帮我解.马上! 解方程组：x/28+y/35+z/30=4.5①；x/35+y/28+z/30②；x+y+z=142③ (20%x+30%y+45%z)/(x+y+z)=35%这个方程怎么解? x*(y-Z)=27,y*(x-Z)=35,Z*(x+y)=28三个方程正整数解 (x+y-z)(x-y+z)= 求解三元一次方程组,x+y+z=142 x/30+y/28+z/35=4.5 X+Y+Z=? (x*x+y*y+z*z)-(X+Y+Z)=?excel公式怎么表达 X+Y+Z=35 X/16+Y/10+Z/20=2.5 Z/16+Y/10+X/20=2.65怎么求x y z