5x 6y 2z=80,4x-3y z=16,3x-2y 6z=92解下列方程组
来源:学生作业帮助网 编辑:作业帮 时间:2024/05/01 01:48:49
1,x+y/2+x-y/3=6即:5x-y=36①4(x+y)-5(x-y)=2即:-x+9y=2②①+②*5==可接2,先化整:3(x+y)+2(x-y)=36①4(x+y)-5(x-y)=2②①*
令a=x+2yb=3x-ya/2+b/3=5(1)0.2a+0.8b=4(2)所以a=20-4b代入(1)10-2b+b/3=55b/3=5b=3a=20-4b=8所以x+2y=8(3)3x-y=3(
原式=(9x²+24xy+16y²-4x²+y²-5x²+6xy-y²)÷(-2y)=(30xy+16y²)÷(-2y)=-15x
(4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=4x-2y-z-5x[6y-(x+y)]+x-(3y-10z)=4x-2y-z-30xy+5x²+5xy+x-3
3x+3y+2x-2y=36①4x+4y-5x+5y=2②(3x+2x)+(3y-2y)=365x+y=36y=36-5x③把③带入②得,-x+9(36-5x)=2x=7把x=7带入③得y=1∴此方程
5x+y=369y-x=2即45y-10+y=36y=1x=7
化简得:-x+7y=11①7x+3y=27②①式×7得:-7x+49y=77③②+③得:52y=104∴y=2代入①得:x=3∴x=3,y=2再问:亲,是代入法哦!再答:代入法①式得3x+3y-4x+
楼上的全错,{(3x+y)(3x-y)-(x-5y)(5x-y)-(x-2y)²}÷(-4x)={9X²-(5x²-xy-25x²+5y²)-(x&s
因为(x-y)/(x+y)=3,则(x+y)/(x-y)=1/3则5(x-y)(x+y)-(x+y)/2(x-y)=5*3-1/(3*2)=15-1/6=89/6
化简x+y=105x+7y=625x+5y+2y=622y=62-50y=6x=4
3x+4y=x+2y+62x-x+4y-2y=62x+2y=6x+y=6/2x+y=3
1、(x+y/4)-(x-y/5)+(x+y/4)+(x-y/5)=-1+32(x+y/4)=2(x+y/4)=1则(x-y/5)=2x+y/4=1列{x-y/5=2之后的一般人都会了吧,不会的就看下
(x+y)/2+(x-y)/3=6①5(x+y)-2(x-y)=4②由①得3x+3y+2x-2y=365x+y=36y=36-5x③由②得5x+5y-2x+2y=43x+7y=4④③代入④得3x+25
设a=x+y,b=x-y原方程组为:a/2+b/3=6,即3a+2b=36,即:12a+8b=1444a-5b=12,即:12a-15b=36相减得:23b=108,得:b=108/23,再得:a=1
条件不完全.补充后给你解答.4x-5y是4x=5y还是缺少了等号后的值?再问:4x-5y=3再答:
题意不清什么是平方,*吗?那么**代表三次方还是4次方呢
(5x+3y)(3y-5x)-(4x-y)(4y+x)=(3y)^2-(5x)^2-(4x^2+15xy-4y^2)=9y^2-25x^2-4x^2-15xy+4y^2=13y^2-15xy-29x^
解析第二个方程式4x+y=3y+x3x=2yy=3x/2带入第一个方程式5x+4y=445x+4*3x/2=445x+6x=4411x=44x=4所以y=3x/2=6x=4,y=6
5x=y,5:y=x,3x=4y,3:x=4:y,3;x=y:43x+4x=y,中X和Y成比例分别成正比反比正比正比反比正比3x+4x=y确定没抄错?要是抄错了就不成比例了因为Y比X得一个常数才能叫成
原式=x-x+x-x+……-x+(2-1+4-3+5-4+……+2008-2007-2009)y=0+(1×1004-2009)y=-1005y=1005/2