已知10^x=3,10^y=2求10的2x 3y平方的值-搜答案-智慧作业帮

x^2-4x+y^2-10y+29=0(x^2-4x+4)+(y^2-10y+25)=0(x-2)^2+(y-5)^2=0x=2,y=5x^2y^2+2x^3y^2+x^4y^2=x^2y^2(1+2

x=y+3∴x-y=34分之一(x-y)的平方-0.3(x-y)+0.75(x-y)的平方+10分之3(x-y）-2（x-y）+7=(0.25+0.75)(x-y)²+(-0.3+0.3-2

即求sqrt(x-3)+y的最大值因为a+

x^2-4x+y^2-10y+29=(x^2-4x+4)+(y^2-10y+25)=(x-2)^2+(y-5)^2=0所以x=2,y=5因此X^2Y^2+2X^3Y^2+X^4Y^2=4*25+2*8

二式乘4得三式,三式减一式得：17X=14得X=14/17将X代入一式,得Y=16/17

5x+2y=6同时乘420x-8y=24用第一个式子加上个式子23x=30x=30/23y代入

很多数学符号,还是写出来方便.

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

x-y-3绝对值+(2x+2y+10)的平方=0X-Y-3=0X-Y=32X+2Y+10=0X+Y=-5(x+y)(x-Y)=3X(-5）=-15

x^2-4x+29-10y+y^2=(x-2)^2+(y-5)^2=0x=2y=5x^2y^2+2x^3y^2+x^4y^2=4*25+2*8*25+16*25=900

X+Y分之X-Y等于3x=-2yX+Y分之2(x-y)减X+Y分之3X+Y=(-x-3y)/(x+y)=1

在坐标系中先作2x+5y≥10对应的直线2x+5y=10,取直线上方区域；然后作2x-3y≥-6对应的直线2x-3y=-6,把y的系数变为正,可知取直线下方区域；最后作2x+y≤10对应的直线2x+y

因为(x-y)/(x+y)=3,则(x＋y)/(x－y)＝1/3则5(x-y)(x+y)-(x+y)/2(x-y)＝5*3-1/(3*2)=15-1/6=89/6

x²-2x+y²+6y+10=0x²-2x+1+y²+6y+9=0(x-1)²+(y+3)²=0x-1=0y+3=0∴x=1y=-3∴x+y

x^2+2x+y^2-6y+10=0（x+1)²+（y-3)²=0∴x=-1,y=3(x+y)²=（-1+3）²=4

3x+4y=104x+3y=-2两式相加7x+7y=87(x+y)=8x+y=8/7

x-2y=3m-2x+y=10y=4-mx=m+6xy4或m

(x+y)²=x²+2xy+y²(x-y)²=x²-2xy+y²两式相加得(x+y)²+(x-y)²=2(x²

（2x-y)³-（2x-y）²（x-3y）=(2x-y)²[(2x-y)-(x-3y)]=(2x-y)²(x+2y)=10²×11=1100

由题意知：x-y=31/4(x-y)²-0.3(x-y)+0.75(x-y)²+3/10(x-y)-2(x-y+7)=(1/4+0.75)(x-y)²+(3/10-0.3