先因式分解 再求值2xy2-2x2y其中y-x=3xy=1 6
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(3x2y-2xy2)-(xy2-2x2y)=3x2y-2xy2-xy2+2x2y=5x2y-3xy2当x=-1,y=2时,原式=5×(-1)2×2-3×(-1)×22=10+12=22.
(x-1)^2+(2x+1)(x-1)+3x^2-3=(x-1)^2+(2x+1)(x-1)+3(x+1)(x-1)=(x-1)(x-1+2x+1+3x+3)=3(x-1)(2x+1)x=根号2/2代
[2x(x2y-xy2)+xy(xy-x2)]÷x2y=[2x3y-2x2y2+x2y2-x3y]÷x2y=x-y,把x=2013,y=2012代入上式得:原式=x-y=2013-2012=1.
原式=xyz(z+y+x)=2/5*7/20*1/4*(2/5+7/20+1/4)=7/200*1=7/200
每一项都提一个xyz得xyz(x+y+z)将值带入得出答案再答:已答请采纳哦亲
原式=2x2+y2−x2−2y2x+y=x2−y2x+y=x-y,当x=2+1,y=22-2时,原式=2+1-22+2=-2+3.
1.x^62.=x^2-y^2+x^2+y^2-2xy-3x^2+xy=-x^2-xy=-10/33.(a-b)(3x+y)(3x-y)
3xy(x²y-xy²+xy)-xy²(2x²-3xy+2x)=3x³y²-3x²y³+3x²y²-
(1).1.(x+18)^2=(22+18)^2=16002.(2a-b)^2=(2*1/2-5/4)^2=1/16(2).(2x-3)^2=0x=3/2(3).xy(a-b)^2=5*6^2=180
(1)[1/(x-1)-1/(x+1)]*(x^2-1)/x=[x+1-(x-1)]/[(x-1)(x+1)]*(x^2-1)/x=[2/(x^2-1)]*[(x^2-1)/x]=2/x根据x=√5,
原式=x²/(x-1)×x(x-1)/(x-1)²=x³当x=2时原式=2³=8再问:x²-1/(x²-1)chux²-x/x
已知:x+y=1,xy=-1/2,利用因式分解求:x(x+y)(x-y)-(x+y)的平方的值.x(x+y)(x-y)-x(x+y)^2=x(x+y)(x-y-x-y)=x(x+y)(-2y)=-2x
原式=2x(a-2)+y(a-2)=(a-2)(2x+y),当a=0.5,x=1.5,y=-2时,原式=(0.5-2)×(3-2)=-1.5.
f(x)=8x^3(x-3)+12x^2(3-x)=4x^2(x-3)(2x-3)x=1.5f(1.5)=4(1.5)^4(1.5-3)(2(1.5)-3)=0
把4x^2(a-3)=y^2(3-a)的左右两边乘以-1,得-4x^2(a-3)=-y^2(a-3)-4x^2(a-3)+y^2(a-3)=0运用分配率得(a-3)(y^2-4x^2)=0即,(a-3
3x²+4x-2x²+x+x²-3x-1=2X^2+2X-1当X=-2时,原式=8-4-1=3.再问:﹣p²-p²-p²-p²合并
原式=2x2y-2xy2+3x2y2-3x2y-3x2y2+3xy2=-x2y+xy2,当x=-12,y=2时,原式=-(−12)2×2+(-12)×22=-52.
a^2-2ab+b^2-5a+5b+6=(a-b)^2-5(a-b)+6=(a-b-2)(a-b-3)=2
3x^2+2x-5x^2+3x=(3x^2-5x^2)+(2x+3x)=-2x^2+5x=-2(-2)^2+5(-2)=-8-10=-18