4m²-9分之x-y

1、x+2y=3.(1)3x-y=5.(2)由(1)知x=3-2y带入（2）得3(3-2y)-y=59-6y-y=5y=4/7x=3-2y=3-8/7=13/72、(x-2)/3=(y+4)/5.(1

x=4m-1/2x+1/2=4m(x+1/2)/4=my=m+1/4y-1/4=m(x+1/2)/4=y-1/4x+1/2=4y-1x+3/2=4y

x/3=y/4=m/5≠0则设x/3=y/4=m/5=t有：x=3ty=4tm=5t代入要求的方程中有：(x+y+m)/(x+y-m)=(3t+4t+5t)/(3t+4t-5t)=6

(m-n-2q)^2=(m-n)^2+4q^2-4q(m-n)=m^2+n^2-2mn+4q^2-4mq+4nq-3分之2(x-y)^2*4分之3(x-y)^4(x-y)3=-2/3(x^2+y^2-

指数是不是写错了?是不是3X^（3m+5n+9)+9y^（4m-2n+3)=5若是,则既然是二元一次方程则指数都等于1,3m+5n+9=14m-2n+3=1解得3m+5n=84m-2n=-2即3m+5

由x/3-y/5=4左右两边都乘以15得出：5x-3y=60x=12+3y/5代入原来的两个方程得出：24+6y/5+y=6m36+9y/5-2y=2m再答：得出：11y/5=6m-24y/5=36-

（x^2-y^2分之M）=(x^2-y^2分之2xy-y^2)+(x+y分之x-y）,M/(x²-y²)=(2xy-y²)/(x-y)(x+y)+(x-y)/(x+y)M

解最简公分母2(x+y)²,∴(x-y)/(2x+2y)=(x+y)(x-y)/2(x+y)²=(x²-y²)/2(x+y)²xy/(x+y)

x-2y=1-m/2.(1)3x+4y=2m.(2)(1)*2+(2)得：5x=2+m.(3)(2)-(1)*3得：10y=7m/2-3.(4)(3)*2-(4)得：10(x-y)=7-3m/2x-y

由方程组①3x＋4y=2m②x－2y=1－½m∴①＋②×2得：x=﹙m＋2﹚／5再代人①得：y=﹙7m－6﹚／20,∴x－y=﹙m＋2﹚／5－﹙7m－6﹚／20＜0解得：m＞14／3.再问：

9分之5x+4y等于5分之3x+2y等于2分之x-y(同时乘以90,得到)50X+40Y=54X+36Y=45X-45Y所以X=Y=0

-6xy-7x^(3m-1)y^2+3分之4x^3y-x^2y-5是七次多项式那么x,y的最高次项的总次数为7最高次项只能是-7x^(3m-1)y^2次数和为3m-1+2=7,∴m=3

a²=m²+12b²=4-m²c²=a²+b²=16c=4所以焦距=2c=8

1/(3a＋2)+3*x*|m|*y^2+（m+2)*x^2y是这样的吗,那个式子再问：诶？^这个符号是几的几次方的意思再答：1/(3a＋2)+3*x^|m|*y^2+（m+2)*x^2y那是这样？我

x-4y分之3x+4y-x分之x+y-x-4y分之7y=3x/(x-4y)-(x+y)/(x-4y)-7y/(x-4y)=(3x-x-y-7y)/(x-4y)=(2x-8y)/(x-4y)=2

x分之4+y分之3=10x分之9-y分之7=-54/x-3/y=10①9/x-7/y=-5②①*123x-4y=120③②*637x-9y=-315④③*36108x-144y=120⑤④*428x-

m=y/x-x/yn=y/x+x/y原式=(m+n)(m-n)=2y/x*(-2x/y)=-4

计算：（1）（n-m分之m+2n）-（m-n分之n）+（n-m分之2m)(2)1.(3m+3n)/(n-m)2.-(55x+1)/9

解最简公分母为x(x-y)(x+y)∴1/(x²-y²)=x/x(x²-y²)=x/x(x-y)(x+y)1/(x²+xy)=(x-y)/x(x+y)