方程4的x次方 6的x次方=6.9的x次方
来源:学生作业帮助网 编辑:作业帮 时间:2024/10/04 13:27:45
4^x+6^x=9^x(2^x)^2+2^x*3^x-(3^x)^2=0把2^x看成未知数来求,得2^x=(根号5-1)*3^x/2整理一下:(3/2)^x=2/(根号5-1)所以x=log3/2为底
两边都乘以X^2-4x=5
x^5-3x^4+2x^3-3x^2+9x-6=0X^3(x^2-3x+2)-3(x^2-3x+2)=0(x^2-3x+2)(X^3-3)=0(x-1)(x-2)(X^3-3)=0x=1或2或3的根号
t=3^x>0t^2-6t-7=0(t-7)(t+1)=0t=7x=log3(7)
4^x+6^x=9^x(4/6)^x+1=(9/6)^x(2/3)^x+1=(3/2)^x((2/3)^x)^2+(2/3)^x-1=0设(2/3)^x=a则:a^2+a-1=0,a>0a=(√5-1
设a=2^x,b=3^x那么方程是:3a^2+2b^2=5ab(3a-2b)(a-b)=0(1):3a-2b=03*2^x=2*3^x(2/3)^x=2/3x=1(2)a-b=03^x=2^x(3/2
设3^x=M,2^x=N,则9^x=3^2x=(3^x)^2=M^2,6^x=MN,2^(2x+1)=2N^2,于是原方程化为:M^2+MN-2N^2=0,分解因式得:(M-2N)(M+N)=0,故M
(x平方+3)(x平方-2)=0(x平方+3)(x+√2)(x-√2)=0∴x=-√2x=√2
设x²=t则t>0t²-t-6=0(t-3)(t+2)=0t=3或-2(舍)∴x=±√3
9^x+4^x=5/2*6^x两边同时除以6^x得:(3/2)^x+(2/3)^x=5/2令t=(3/2)^x,则方程化为;t+1/t=5/2t^2-5/2*t+1=0(t-2)(t-1/2)=0t=
约为0.93,帮你弄了两个过程,你看下吧1)设6^x=a4^x=b9^x=a+b那么log(6)a=log(4)b=log(9)a+b用换底公式lga/lg6=lgb/lg4=lga+b/lg9然后整
4^x+6^x=9^x方程两边同除以9^x得:(4/9)^x+(2/3)^x=1令t=(2/3)^x则,(4/9)^x=t²原式为;t²+t-1=0由求根公式得;t=(-1±√5)
6^x+4^x=9^x两边同除以9^x,可得:(2/3)^x+(2/3)^(2x)=1,令y=(2/3)^x,可得:y+y^2=1,即:y^2+y-1=0,解得:y=(√5-1)/2,(舍去负值)即:
4^x+4^(-x)-6*[2^x+2^(-x)]+10=0设2^x+2^(-x)=t>0t^2-6t+8=0(t-2)(t-4)=0t=2或t=42^x+2^(-x)=2x=02^x+2^(-x)=
令3^x=a则9^x=a²a²-6x-7=0(a-7)(a+1)=0a=3^x>0所以3^x=a=7x=log3(7)
1/2的X次方乘以8的2X次方=42的-X次方乘以2的6X次方=2的2次方6x-x=25x=2x=0.4再问:化简2的4+log23的次方
∵x的6次方>=0∴x的6次方+2>0∴方程x的6次方+2=0无解
-2答案不唯一
(x+1)(x+4)=x的2次方-6x²+5x+4=x²-65x=-10x=-2
是4^x+6^x=6*9^x吧?两边同除以9^x:(4/9)^x+(6/9)^x=6即(2/3)^2x+(2/3)^2-6=0[(2/3)^x+3][(2/3)^x-2]=0因(2/3)^x>0所以只