作业帮5x-2=6y-3
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/14 15:34:43
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
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
{(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
2(2x+3y)(3x+2y)-(6x-y)(2x-5y)=12x^2+26xy+12y^2-(12x^2-32xy+5y^2)=12x^2+26xy+12y^2-12x^2+32xy-5y^2=58
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
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
｛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
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
解(x-y)(x+y)-(x-2y)²+x(3x-5y)-(x-y)(x-2y)=(x²-y²)-(x²-4xy+4y²)+(3x²-5xy
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
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则y=3-x带入x+2y=9解得x=-3,y=6剩下的都这样解