求x的..1.3^(5x)X9^(x^2)=272.3^(x+2)=5^(x-1)3.logx+log(x-9)=14.logx-log(x+3)=-15.log4(x+3)+log4(x-3)=24是底数

Question

求x的..
1.3^(5x) X 9^(x^2)=27
2.3^(x+2) = 5^(x-1)
3.log x + log (x-9)=1
4.log x - log (x+3)=-1
5.log4 (x+3) + log4 (x-3)=2 4是底数

Answer 1

1.3^(5x) * 9^(x^2)=279=3^2 27=3^3所以嘞可以写成5x+2x^2=3解得x=-3或x=1/22.3^(x+2) = 5^(x-1)3^x*9=5^x/545=(5/3)^xx=log(5/3)45 (5/3)是底数3.log x + log (x-9)=1x*(x-9)=(题目的底数)4.log x - log (x+3)=-1x/...