已知x的n次方等于5 y的2n次方等于3求下列各式的值
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x^n=2,y^n=3(x^2y^2)^(2n)=(xy)^(4n)=(x^ny^n)^4=(2*3)^4=1296
解x^n=5y^n=3所以(xy)^n=15所以(xy)^2n=[(xy)^n]^2=15^2=225希望对你哟帮助学习进步O(∩_∩)O
x^(6n)+y^(4n)=[x^(3n)]^2+[y^(2n)]^2=5×5+4×4=25+16=41
20次则2m+3n=20不能求出m和n的具体值
x的n次方等于4,y的n次方等于3x乘以y的2n次方=(x的n次方)²×﹙y的n次方﹚²=4²×3²=144
(xy)2N=x2n·y2n∵xn=5,yn=3,∴x2n=25,y2n=9∴(xy)2N=25·9=225加油学习数学哦~再问:我还要问道题再答:嗯,本人自信数学很好~~哈哈再问:哦*--
x^n=2y^n=3(x^2*y)^2n=x^4n*y^2n=(x^n)^4*(y^n)^2=2^4*3^2=16*9=144
你先把算式写出来,等于2的3n+3次方乘以1/2的3n+3次方,等于1. 这道题考察幂的运算,一个数a的m次方乘以a的n次方等于a的(m+n)次方;一个数(b的m次方)的n次方等于b的(m×
5x^(3n+5)y^(3m-1)÷[-5x^(n+1)y^m]^2=x^2/55x^(3n+5)y^(3m-1)÷25x^(2n+2)y^2m=x^2/51/5*x^(3n+5-2n-2)y^(3m
[x^(2n)-y^(2n)]/[x^(n)+y^(n)]=(x^n-y^n)*(x^n+y^n)/(x^n+y^n)=x^n-y^n
(xy)^(2n)=[(x^n)(y^n)]^2=[5×4]^2=400再问:^是什么意思呀
18=2*3^218=x^(1/n)*y^(2/n)18=(xy^2)^(1/n)18^n=xy^2
x^2*x^2n*y^2n=x^2*(xy)^2n=(-4)^2*(-4*1/4)^2n=16*(-1)^2n=16*1=16再问:不好意思,题打错了...是2n+1...不是2n..再答:x^2*x
左边括号内丢了个系数吧{2×x^5m*y^2(m-n)}³=8x^6*y^158x^(15m)*y^(6(m-n))=8x^6*y^15等式左右相应项的次数相等∴15m=6,6(m-n)=1
(XY)^2n=x^2n*y^2n=(x^n)^2*(y^n)^2=25*9=225
(XY)^2N=[(XY)^N]^2=[(X^N)(Y^N)]^2=(5x3)^2=15^2=225
应该是这样的:=X的N次的平方*Y的N次的3次方=(5*5)*(3*3*3)=675
x^(6n)+x^(4n)*x^(5n)=x^(6n)+x^(9n)=[x^(3n)]^2+[x^(3n)]^3=2^2+2^3=4+8=12
依题意:x^(15m+3n)*y(6m-3n)=x^6*y^15对比两边幂数可得:15m+3n=6……①6m-3n=15……②①+②得:21m=21∴m=1∴n=-3∴n的m次方=-3
取对数n=lg|Y|/lg|X|