5x-6y=13 3x 4y=4
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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*
设(x+y)为t,(x-y)为p,所求的解为c所以t/2+p/2=64t-5p=c整理得:5t+5p=604t-5p=c两式相加得9t=60+cc=9t-60所以4(x+y)-5(x-y)=9(x+y
我怕来不及,等等发给你!再问:慢慢来,,,,,,再问:还没好??
设x-y=mx+y=n则6m-2n=143m+n=5解得m=2n=-1即x-y=2x+y=-1解得x=1/2y=-3/2
由(1)得3x+3y+2x-2y=365x+y=36(3)由(2)得4x+4y-3x+3y=-20x+7y=-20(4)(3)×7-(4)得34x=272∴x=8把x=8代入(3)得y=-4∴x=8y
多项式2x3y2-3x2y3-5x4y+6xy4-5中,x的系数依次3,2,4,1,按x的降幂排列是-5x4y+2x3y2-3x2y3+6xy4-5.
{(x+y)/2+(x-y)/3=63(x+y)+2(x-y)=36(1)4(x+y)-3(x-y)=-20(2)由(1)*3+(2)*2得9(x+y)+6(x-y)+8(x+y)-6(x-y)=36
3x+4y=x+2y+62x-x+4y-2y=62x+2y=6x+y=6/2x+y=3
(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
5(x-y)^3*[-6/25(y-x)^3][-2/3(y-x)^4]=5(x-y)^3*[4/25(y-x)^7]=(x-y)^3*{2/5[-(x-y)]^7}=-2/5(x-y)^10
先将第一个等式整理得12X+Y=36,第二个等式整理得-X+9Y=2,由第一个等式得Y=36-12X,通过换元法得-X+9(36-12X)=2,解出X=322/109,再把X=322/109代入-X+
题意不清什么是平方,*吗?那么**代表三次方还是4次方呢
3(x+y)-4(x-y)=4(x+y)/2+(x-y)/6=1令a=x+y,b=x-y3a-4b=4(1)a/2+b/6=1则3a+b=6(2)(2)-(1)5b=2b=2/5a=(6-b)/3=2
∵-2x3m+1y2n•4xn-6y-3-m=-8x3m+n-5y2n-3-m,又∵-2x3m+1y2n与4xn-6y-3-m的积与-4x4y是同类项,∴3m+n−5=42n−3−m=1,解得:m=2
x=7/3.y=1/3
3x+2y/4=2x+y/5可得x=-3y/10x-y+1/6=2x+y/5x=-6y/5+1/6-3y/10=-6y/5+1/6y=5/27x=-1/18
5@6=4×5-3×6=20-18=2
5@6=4×5-5×6=20-30=-10再问:详细点!!~~(*^__^*)嘻嘻……(答案(^_^)不错嘛)再答:把x=5,y=6带入4x-5y就行
应该是3X=4Y,5Y=6Z吧?X+Y:Y+Z=[(4Y/3)+Y]:(Y+5Y/6)=14;11