己知-x 3y=5求5(x-3y)的平方-8(x一3y)-5的值
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∵|2x-3y+1|+(x+3y+5)的二次方=0∴2x-3y+1=0x+3y+5=0x=-2y=-1∴(-2x*y)的二次方(-y的二次方)×6xy平方的值=4x⁴y*(-y²
x3y+2x2y2+xy3=xy(x2+2xy+y2)=xy(x+y)2,∵x+y=5,∴(x+y)2=25,x2+y2+2xy=25,∵x2+y2=13,∴xy=6,∴xy(x+y)2=6×25=1
原式=(x4-xy3)+(y4-x3y)+(3xy2-3x2y)=x(x3-y3)+y(y3-x3)+3xy(y-x)=(x3-y3)(x-y)-3xy(x-y)=(x-y)(x3-y3-3xy)=(
∵x+y=4,∴(x+y)2=16,∴x2+y2+2xy=16,而x2+y2=14,∴xy=1,∴x3y-2x2y2+xy3=xy(x2-2xy+y2)=14-2=12.
∵Y是(-5)2次幂的平方根∴Y=±5∵X+Y的负的平方根-3,∴X+Y=9X±5=9∴X=14或X=4当X=14,Y=5时,2X-5Y=28-25=3;当X=14,Y=-5时,2X-5Y=28-(-
原式=x4+x3y+4x3y+x2y+4x2y2+4x2y2+xy2+4xy3+xy3+y4,=x3(x+y)+4x2y(x+y)+xy(x+y)+4xy2(x+y)+y3(x+y),=-x3-4x2
y=(5分之1)x+b解出x,也就是用y表示x,得到x=5y-5b,则y=(5分之1)x+b的反函数是y=5x-5b,因为y=(5分之1)x+b与y=ax+3互为反函数,所以y=5x-5b也就是y=a
第一个式子两边都乘以3,得到:15x-9y=36第二个式子两边都乘以5,得到:15x+20y=-40将所得的两个式子相减得到:29y=-76解得:y=-76/29将所得结果代入已知的任一方程解得:x=
X+Y=2(1)X-Y=4(2)由(1)(2)得X=3,Y=-1把X,Y带入2ax-by=5,ax+3by=6得6a+b=5(3)3a-3b=6(4)解得a=1,b=-1
已知x+y=5,xy=3,代数式x3y-2x平方y平方+xy3=xy(x²-2xy+y²)=xy(x-y)²=3×[(x+y)²-4xy]=3×(25-12)=
再答:不明白的地方可以追问,望采纳,谢谢
∵|x+y+1|≥0,|xy-3|≥0|x+y+1|+|xy-3|=0,∴x+y+1=0,即x+y=-1xy=3xy3+x3y=xy(x²+y²)=yx[(x+y)²-2
x3y+xy3=xy(x^2+y^2)=(√3-√2)(√3+√2)((√3-√2)^2)+(√3-√2)^2)=1*(3-2√6+2+3+2√6+2)=10
(x-y)2=x2-2xy+y2=9,当x2+y2=13时,13-2xy=9,解得xy=2.当xy=2,x2+y2=13时,x3y-8x2y2+xy3=xy(x2-8xy+y2)=2×(13-8×2)
X=1,Y=2,XY=2;
x(x十y)(x一y)一x(x十y)²=x(x十y)[(x一y)一(x十y)]=x(x十y)*(-2y)=-2xy(x+y)=-2*6*5=-60
∵x-y=l,xy=2,∴x3y-2x2y2+xy3=xy(x2-2xy+y2)=xy(x-y)2=2×1=2.
原式=4xy+8y+6x+2xy-5y-3x=6xy+3x+3y=6*3+3(x+y)=18-12=6
2x+3y=-k+2,①3x-2y=5k+3②2*①+3*②13x=13k+13所以x=k+1代入①y=-kx-y=2k+1=5k=2