(a^m+1b^n+2)(a^2n-1b^2m)=a^5b^3,求m-3n的值是求m-3n的值,急,明天要交的还有一da题:用简便方法计算下列各题:①2^5*5^4②(-3)^5*(-2/3)^5*(-5)^6
问题描述:
(a^m+1b^n+2)(a^2n-1b^2m)=a^5b^3,求m-3n的值
是求m-3n的值,急,明天要交的
还有一da题:用简便方法计算下列各题:①2^5*5^4
②(-3)^5*(-2/3)^5*(-5)^6
答
(a^m+1b^n+2)(a^2n-1b^2m)=a^5b^3,求m-3n的值
(a^m+1b^n+2)(a^2n-1b^2m)=a^5b^3
a^(m+1+2n-1)b^(n+2+2m)=a^5b^3
∴m+2n=5
2m+n+2=3
m=-1
n=2
∴m-3n =-1-6=-7
①2^5*5^4
=2×5×2×5×2×5×2×5×2
=20000
②(-3)^5*(-2/3)^5*(-5)^6
=(-3)^5×(-2/3)^5×5^5×5
=[(-3)×(-2/3)×5]^5×5
=10^5×5
=500000