23x 12y=5,x-3y=6求

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23x 12y=5,x-3y=6求
x+y/2+x-y/3=6,4(x+y)-5(x-y)=2用加减消元法解方程组

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*

3x+2y=6 ,5x+6y=10那么x+y=?

3x+2y=6,5x+6y=10两个式子相加,得8x+8y=16x+y=23x^2-4x+6=12,3x^2-4x=6则x^2-(4x+2)/3=1/3(3x^2-4x-2)=1/3(6-2)=4/3

6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5

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

{x=5y 3x+6y=42

x=5y代入3x+6y=42得到15y+6y=4221y=42y=2那么x=5y=10希望能帮你忙,不懂请追问,懂了请采纳,谢谢

已知x.x+y.y-6x-8y+25=0,求3x.x+5y的值

可以得出x.x+y.y-6x-8y+25=x.x-6x+9+y.y-8y+16=(x-3).(x-3)+(y-4).(y-4)=0因为(x-3).(x-3)>=0,(y-4).(y-4)>=0所以x=

已知x,y满足约束条件{2x+5y>=10,2x-3y>=-6,2x+y

在坐标系中先作2x+5y≥10对应的直线2x+5y=10,取直线上方区域;然后作2x-3y≥-6对应的直线2x-3y=-6,把y的系数变为正,可知取直线下方区域;最后作2x+y≤10对应的直线2x+y

已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)

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

二元一次方程的解法 2X-4Y=6 3Y=X+5 2X+3X=7 3X+5Y=53X+2Y=17 2X+5X=23 3X

2X-4Y=6(1)3X+2Y=17(2)(1)+(2)*22X+3X*2-4Y+2Y*2=6+17*28X=40X=5Y=6-2*5/(-4)=13Y=X+5(1)2X+5X=23(2)(题目可能有

解二元一次方程组:{5(x+y)+3(x-y)=2{7(x+y)-3(x-y)=-6

{5(x+y)+3(x-y)=2{7(x+y)-3(x-y)=-6原方程组化简得﹛4x+y=1(1)2x+5y=-3(2)(1)×5得20x+5y=5(3)(3)-(2)得18x=8x=4/9代入(1

若5x+3y=3x+4y=x+2y+6,则x+y=___

3x+4y=x+2y+62x-x+4y-2y=62x+2y=6x+y=6/2x+y=3

解方程组 {(x+y)/2+(x-y)/3=6 5(x+y)-2(x-y)=4

(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

解方程组:x+y/2+x-y/3=6 4(x+y)-5(x-y)=12

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

先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y

解(x-y)(x+y)-(x-2y)²+x(3x-5y)-(x-y)(x-2y)=(x²-y²)-(x²-4xy+4y²)+(3x²-5xy

解方程组 X+Y/2+X-Y/3=6 4[X+Y]-5[X-Y]=2

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+

4x-2y-6y*-y-3x+5y* *=2 就是平方

题意不清什么是平方,*吗?那么**代表三次方还是4次方呢

3x+2y/4=2x+y/5=x-y+1/6

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

x+y=3 x+2y=9 3/x+1=y y-x=3 y=2x-3 y-3x=1 2(x+1)-y=6 7x-5y=-9

x+y=3则y=3-x带入x+2y=9解得x=-3,y=6剩下的都这样解