圆x²+y²+4x-6y+3=0的半径为
来源:学生作业帮助网 编辑:作业帮 时间:2024/05/28 08:15:12
原式=-(x-y)³(x-y-1)
写清楚点点比如说前面是X/X还是X/(X-Y)打上括号分段这样才能清楚的做
6*(x+y)^7-9*(x+y)^3*(x-y)^2*((3*x-3*y)*(x+y))^(1/2)ok?再问:可不可以写清楚点
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
原式=(x+y)^18-3(x+y)^18*(x+y)^4*(x+y)^2=(x+y)^18-3(x+y)^(18+4+2)=(x+y)^18-3(x+y)^24
3(X-Y)²-4(X-Y)+7(X-Y)-6(X-Y)²=(3-6)(X-Y)²+(-4+7)(X-Y)=-3(X-Y)²+3(X-Y)
解题思路:由完全平方公式、非负数的和等于0,可解。、解题过程:已知x²+y²-4x+6y+13=0,求x,y的值解:x²+y²-4x+6y+13=0x²-4x+4+y²+6y+9=0(x-2)²+(y
(x+y)-(2x+y/2)-(3x+y/6)-(4x+y/12)-(5x+y/20)-……-(10x+y/90)=x-2x-3x-4x-..-10x+y*(1-1/2-1/6-1/12-..1/90
解题思路:对于这种等式一定可以化成平方相加的形式,这里面要使用到完全平方公式。解题过程:
原式=3x-4y+(2y+x)-(x-3y)-6x=-3x-4y+(2y+x)-(x-3y)=-3x-4y+2y+x-x+3y=-3x+y
第二个方程是不是写错了2/(x+y)+3/(x-y)=6是这样吗
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
解题思路:先利用完全平方公式求出x、y的值,再代入求出代数式的值。解题过程:
1.((y+2x)(-2x+y)+4(x+2y)^2)/3y=(y^2-4x^2+4x^2+16xy+16y^2)/3y=(17y^2+16xy)/3y=17y/3+16x/32.(2(x-y)^3-
(3x-4y)(5x-4y)-(7x-8y)(6y-5x)=15x²-12xy-20xy+16y²-(42xy-35x²-48y²+40xy)=15x²
完整设1/(x+y)=a,1/(x-y)=b原方程组可变为4a+6b=39b-a=1a=9b-136b-4+6b=3b=1/6,a=1/2x+y=2x-y=6所以原方程组的解为:x=4,y=-2
原式等于2x^2-xy+6xy-3y^2-8x+4y=2x^2+5xy-3y^2-8x+4y
x²+y²-4x+6y+13=0x²-4x+4+y²+6y+9=0(x-2)²+(y+3)²=0x=2,y=-3代入即可得出答案(3x+y)