y=-x2 7x-10

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如果2x-y=10,求代数式[(x²+y²)-(x-y)²+2y(x-y)]÷4y的值

如果2x-y=10那么[(x²+y²)-(x-y)²+2y(x-y)]÷4y=[(x²+y²)-(x²-2xy+y²)+(2xy-

已知2x+y=10,求代数式((x+y)的平方-(x-y)的平方-2y(x-1/2y))/4y的值

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+

(4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai

(4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=4x-2y-z-5x[6y-(x+y)]+x-(3y-10z)=4x-2y-z-30xy+5x²+5xy+x-3

已知2x-y=10,求式子[(x^2+y^2)-(x-y)^2+2y(x-y)]/4y

[(x^2+y^2)-(x-y)^2+2y(x-y)]/4y=[(x^2+y^2)-(x^2-2xy+y^2)+2xy-2y^2]/4y=[x^2+y^2-x^2+2xy-y^2+2xy-2y^2]/

已知x+y=10,求[(x+y)^2-(x-y)^2-2y(x-y)]÷5y的值

[(x+y)²-(x-y)²-2y(x-y)]÷5y=[X²+2XY+Y²-X²+2XY-Y²-2XY+2Y²]÷5Y=[2Y(X

已知2x-y=10,求[(x²+y²)-(x-y)²+2y(x-y)]/4y

先化简[(x²+y²)-(x-y)²+2y(x-y)]/4y[(x²+y²)-(x-y)²+2y(x-y)]/4y=[x²+y&s

10(8-y)+6y=56

80-10y+6y=5680-56=10y-6y24=4yy=6

已知/x/+x+y=10,/y/+x-y=12.求x+y的值

|x|+x+y=10|y|+x-y=12两式相加得|x|+|y|+2x=22.(1)两式相减得|x|-|y|+2y=-2.(2)所以-|y|+2y<0若y>0,则显然-y+2y<0,即y<0,矛盾若y

X+Y=7(100X+Y)-(10Y+X)=(10Y+X)-(10X+Y)

(100X+Y)-(10Y+X)=(10Y+X)-(10X+Y)100X+Y-10Y-X=10Y+X-10X-Y99X-9Y=9Y-9X-18Y=-108XY=6X把Y=6X代入X+Y=7得X+6X=

已知2x-y=10,求式子[(x^2+y^2)-(x-y)^2+2y(x-y)]/4y (4xy-2y²)/4

已知2x-y=10,式子[(x^2+y^2)-(x-y)^2+2y(x-y)]/4y=[x^2+y^2-x^2+2xy-y^2+2xy-2y^2]/4y=[4xy-2y^2]/4y=2y(2x-y)/

# include main (){ int y=10;for( ; y>0; y - -)if ("y%3" == 0

y--是:y的值先用来运算,再减去1--y是:y的值先减去1再用来运算.此处for内部为一个循环.y的值从10依次减1if语句内表示y处以3余数为零,如果满足则打印y-1的值.比如y=10,则不满足条

80y+100y=x+60(y+10)+100(y+10) 这个方程怎么解?

1.设甲距离乙.丙为A,100*10=60*10+A1000=600+A100*20=80*20+A2000=1600+AA=400.开始甲和乙丙相距400米.2.80y+100y=x+60y+600

10y+2(7y-2)=5(4y+3)+3y怎么算

10y+2(7y-2)=5(4y+3)+3y10y+14y-4=20y+15+3y10y+14y-20y-3y=15+4y=19

2.5y+10y-6y=15-21.5

2.5y+10y-6y=15-21.56.5y=-6.5y=-6.5÷6.5y=-1

y-12/y=?

(y^2-12)/y

已知实数x,y满足|x|+x+y=10、x+|y|-y=12,则x+y的值?

若x≤0,|x|=-x|x|+x+y=10y=10代入x+|y|-y=12得x=12>0矛盾,∴x>02x+y=10①若y≥0,x+|y|-y=x=12y=10-2x∴yx-2y=12②联立①②解得x