5的X次方是3,5的Y次方是4,25的X加Y次方是带理由及计算 方法
问题描述:
5的X次方是3,5的Y次方是4,25的X加Y次方是
带理由及计算 方法
答
25^(x+y)=(5^2)^(x+y)=5^(2(x+y))=(5^(x+y))^2=((5^x)*(5^y))^2=(3*4)^2=144
答
5^x=3
5^y=4
25^(X+Y)
=25^x×25^y
=(5^x)²×(5^y)²
=3²×4²
=9×16
=144
答
5^x=3
5^y=4
25^(x+y)
=5^2(x+y)
=[5^(x+y)]^2
=(5^x*5^y)^2
=(3*4)^2
=12^2
=144
答
5^x=3,5^y=4,
∴25^(x+y)=5^(2x+2y)=5^2x×5^2y=3^2×4^2=144