Step-by-step explanation:
[tex]3^x=9^{x+5}\\\\3^x=\left(3^2\right)^{x+5}\qquad|\text{use}\ (a^n)^m=a^{nm}\\\\3^x=3^{2(x+5)}\iff x=2(x+5)\qquad|\text{use the distributive property}\\\\x=2x+10\quad|\text{subtract}\ 2x\ \text{from both sides}\\\\-x=10\qquad|\text{change the signs}\\\\\huge\boxed{x=-10}[/tex]
[tex]27^{4x}=9^{x+1}\\\\\left(3^3\right)^{4x}=\left(3^2\right)^{x+1}\\\\3^{(3)(4x)}=3^{2(x+1)}\iff(3)(4x)=2(x+1)\\\\12x=2x+2\qquad|\text{subtract}\ 2x\ \text{from both sides}\\\\10x=2\qquad|\text{divide both sides by 10}\\\\x=\dfrac{2}{10}\\\\\huge\boxed{x=0.2}[/tex]
[tex]5^x=25^{3x+5}\\\\5^x=\left(5^2\right)^{3x+5}\\\\5^x=5^{2(3x+5)}\iff x=2(3x+5)\\\\x=(2)(3x)+(2)(5)\\\\x=6x+10\qquad|\text{subtract}\ 6x\ \text{from both sides}\\\\-5x=10\qquad|\text{divide both sides by (-5)}\\\\\huge\boxed{x=-2}[/tex]