a^n=8
a^mn=64
(a^n)^m=8^2
8^m=8^2
m=2
a^m=3,a^n=5
a^(m-n)
=a^m÷a^n
=5/3
a^(3m-2n)
=(a^3m)÷a^2n
=(a^m)^3÷(a^n)^2
=3^3÷5^2
=27/25
2^x=1/32
2^x=(1/2)^5
2^x=2^(-5)
x=-5
(2)若(-2)^x = (-2)^3÷(-2)^2x 则x=
(-2)^x = (-2)^(3-2x)
x=3-2x
3x=3
x=1
(3)若0.000 000 3*10^x=3×10^3,则x=
0.000 000 3*10^x=3×10^3
3×10^(-7)*10^x=3×10^3
3×10^(x-7)=3×10^3
10^(x-7)=10^3
x-7=3
x=10
自己思考!
1:m=amn/an=64/8=8
2:(1)a(m-n)=am-an=3-5=-2
(2)5am=3an 5m=3n 3m=(9/5)n
a(3m-2n)=a(9/5)n-a2n=(-1/5)an=-1
3:(1)2x=1/32 x=1/64
(2)(-2)x=3/2x -4x^2=3 x^2=-3/4 x=你确定这个可以是虚数么……
(3)问题很给力
(4)(3/2)x=1/9 x=(1/9)*2/3=2/27
989
1:已知AN=8 AMN=64 AMN=ANxM 既8xM=64 ∴M=8
2∵A3M-2N=3 ,AM=3 AN=5 且A3M-2N=3 既A3M-2N=AM 又∵AM=3 ∴ 9-2N=3 ∴N=3
又∵AN=5 ∴A=5÷3 又∵AM=3 ∴M=3÷A =3÷A =3÷(5÷3)
∴AM-N= (5÷3)X{ 3÷(5÷3)}—3
既AM-N=0