已知5^m=3,5^n=4,求(1)5^2m+5^3n的值:(2)5^2m+3n的值

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已知5^m=3,5^n=4,求(1)5^2m+5^3n的值:(2)5^2m+3n的值

已知5^m=3,5^n=4,求(1)5^2m+5^3n的值:(2)5^2m+3n的值
已知5^m=3,5^n=4,求(1)5^2m+5^3n的值:(2)5^2m+3n的值

已知5^m=3,5^n=4,求(1)5^2m+5^3n的值:(2)5^2m+3n的值
5^m=3,5^n=4
所以
(1)5^2m+5^3n
=(5^m)²+(5^n)³
=3²+4³
=9+64
=73
(2)5^2m+3n
=5^2m×5^3n
=(5^m)²×(5^n)³
=3²×4³
=9×64
=576


(1)
5^(2m)+5^(3n)
=(5^m)² + (5^n)³
=3²+4³
=73
(2)
5^(2m+3n)
=[5^(2m)]*[5^(3n)]
=(5^m)² × (5^n)³
=3²×4³
=576

整体替换的思想。
(1)5^2m+5^3n=(5^m)^2+(5^n)^3=3^2+4^3=9+64=73
(2)5^2m+3n=(5^m)^2*(5^n)^3=3^2*4^3=576