x(1 20%)-y(1-10%)=780
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1/40再问:过程再答:我想让您再发一遍原式行吗?((x+y)的平方-(x-y)的平方-2y(x-1/2y))/4y里的“x-1/2y”是(x-1)/2y还是x-(1/2y)?再问:第二个再答:(x+
x-y/7-x+y/10=1/2两边乘7010x-10y-7x-7y=353x-17y=35(1)2(x-y)+5(x+y)=32x-2y+5x+5y=37x+3y=3(2)(2)*3-(1)*79y
(x+y)/6+(x-y)/10=3①(x+y)/6+(y-x)/10=-1②①可变为:(x+y)/6-(y-x)/10=3③②+③=(x+y)/3=2得x+y=6④②-③=(y-x)/5=-4得y-
原式=(4XY-2X)*(2X+2Y-1)-16XY-4X*X+4Y*Y+XY=8XXY-4XX+8XYY-4XY-4XY+2X-16XY-4XX+4YY+XY
25(x-y)^2+10(y-x)+1=25(x-y)^2-10(x-y)+1={5(x-y)-1}^2=(5x-5y+1)^2
很多数学符号,还是写出来方便.
十字相乘下.10x+2y=7x+10y3x=7yx/y=7/3
2x+y=(4x-y-1)/2=(10+6x+2y)/44x+2y=4x-y-18x+4y=10+6x+2y3y=-12x+2y=10x+y=5y=-1/3x=16/3
1)x(x-y)(x+y)-x(x+y)^2=x((x-y)(x+y)-(x+y)^2)=x(x^2-y^2-x^2-2xy-y^2)=x(-2xy-2y^2)=-2xy(x+y)2)(2a+b)(2
[(-x-y)(-x+y)-(x+y)^2-x(y-y^2)}÷1/2y=[x²-y²-x²-2xy-y²-xy+xy²]/(y/2)=[(x-2)y
若是y的10次,我也不必说了若是y的10阶导数1:1/(1+x)2:-(1+x)^(-2)3:2(1+x)^(-3)……10:9!(1+x)^(-9)
.死算呗xy-2x+3y-6=xy+10x-3y-30,2x-y=4xy+3x+y+3=xy+12x-2y-24,3x-y=92式减1式,x=5,y=6
①-②可得:x-y/10-y-x/10=4x-y/5=4x-y=20——③①+②可得:x+y/3=2x+y=6——④由③④可得:x=13,y=-7
原式=25(x-y)的平方-10(x-y)+1=【5(x-y)-1】的平方=(5x-5y-1)的平方如还有新的问题,请不要追问的形式发送,另外发问题并向我求助或在追问处发送问题链接地址,
(1)x^2/x)-y-x-y=x-y-x-y=-2y(2)(a/a-b)-(a/a+b)-(2b^2/a^2-b^2)=a(a+b-a+b)/(a^2-b^2)-(2b^2/a^2-b^2)=2b/
(0.2x+0.1y)/2-(4x-y)/10=(x-y)/5+(3x+0.5y)/30①(3x+2y-1)/8=3-(0.8x-5y)/41②①两边同时乘以60得(6x+3y)-(24x-6y)=(
19(a-b)^2-16(a+b)^2=-7a^2-50ab-7b^2=-(7a+b)(a+7b)23x^3-12x^2y+12xy^2=3x(x^2-4xy+4y^2)=3x(x-2y)^2325(
(1).4x^3y^4-10x^2y^3+2x^2y^2=2x^2y^2(2xy^2-5y+2)(2).1/2a^2(x-2a)^2-1/4a(2a-x)^3;=1/2a^2(2a-x)^2-1/4a
(x+y)-(2x+1/2y)-(3x+1/6y)-(4x+1/12y)-(5x+1/20y)-.-(10x+1/90y)=x+y-2x-1/2y--3x-1/6y-4x-1/12y-5x-1/20y