解方程组x-3x-1 2=2y,x:2=y:3
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3x-2y=12(1)5x-3y=19(2)(2)-(1)得2x-y=7y=2x-7(3)把该式代入上面任意一式解出x=2y=-3
3x+2y=35y+12x=3将一式*4,得到12x+8y=12,12x=12-8y根据二式12x=3-5y所以:12-8y=3-5y移项:8y-5y=12-33y=9,所以y=3代入,得到x=-1
2x+3y=12(1)3x+4y=17(2)(2)*3-(2)*29y-8y=36-34y=2(2)*3-(1)*49x-8x=51-48x=33(x-1)=y+5(3)5(y-1)=3(x+5)(4
3x+y=k①x+3y=2②②乘以3,得3x+9y=6③③减去①,得8y=6-ky=(6-k)/8将y=(6-k)/8代入②中,得x+3(6-k)/8=2x=2-3(6-k)/8因为x,y
y=3(x-y),x=2(x-y)x=0y=0再问:请问,怎样解=0,要过程,谢谢再答:y=3(x-y)=3x-3y4y=3xy=3x/4x=2(x-y)=2x-2y=2x-3x/2=x/2x-x/2
2x+3y=-1(1)12x-2y=-1(2)由(1)得12x=-6-18y(3)把(3)代入(2)得20y=-5所以y=-1/4把y=-1/4代入(3)得x=-1/8
.死算呗xy-2x+3y-6=xy+10x-3y-30,2x-y=4xy+3x+y+3=xy+12x-2y-24,3x-y=92式减1式,x=5,y=6
X:Y:Z=1:2:3则Y=2X,Z=3X代入X+Y+Z=12,得X+2X+3X=12解得X=2,则Y=2X=4Z=3X=6
3x+2y=3(1)12x+5y=-3(2)(1)×4-(2):8y-5y=12+33y=15y=5带入到(1)中:3x+10=33x=-7x=-7/3所以:x=-7/3y=5秋风燕燕为您解答有什么不
2x+3y=12.A3x+4y=17.B3A-2B得y=2,x=3.
合并方程组:x+y/2=3x-2y;3x-2y=10+6x+y/4;得出:x=5y/4;从而算出:x=-25/12,y=-5/3.手机打很累.
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
由2x+y=1得y=-2x+1,函数y=-2x+1经过(0,1)和(,0),图象如图.由x-2y=3得,函数经过(0,)和(3,0),图象如图.由图可知A点的坐标是:A(1,-1),即方程组的解为.
y=85/18x=59/9再问:过程再答:x+2y=16..........................................1x-y=1/12+3/4+1=11/6..........
{3x-4y(x-y)=3,2x-3y=12x-3y=1,得x-y=(1+y)/23x-4y(x-y)=3,代入x-y=(1+y)/2,得3x-2y(1+y)=33x-2y-2y²=34y+
x=2y=3追问
若3x>y则方程互相矛盾,所以3x<>y,解得x=9/10,y=21/5
x+y/3=x-y/4⑴2x+3y=11⑵由⑴得x+7y=0,x=-7y(3)将(3)代入⑵得y=-1所以x=7
1)1/2x-2y=-74,①x-6y=-12②2①-②得2y=136y=68代入①得x=4202)x/5-y/2=2,化简2x-5y=20①2x+3y=4②①-②得-8y=16y=-2代入①得2x=
可能是0<X0=X0≤X≤1X>1当0<X时,|X+Y|=1原式=Y-X=1Y=1+X|X|+2|Y|=3变2(1+X)-X=3X=1所以Y=0当0=X时Y无解,不成立.当0≤X≤1时X+Y=1X+2