Change of the base rule of logarithm function is used to convert the base of the logarithm to the base of 10 or e form. The value x for the given function is 1.469743. Hence the option 3 is the correct option.
Given information-
The given function in the problem is,
[tex]3^{x+1}=15[/tex]
Change of the base rule of logarithm function is used to convert the base of the logarithm to the base of 10 or e form.
Suppose y and b are the positive real numbers and e is the exponential number. Then by the change of the base rule we can write,
[tex]\log_b y=\dfrac{\log_e y}{\log_e b}[/tex]
[tex]\log_b y=\dfrac{\log y}{\log b}[/tex]
The given function is,
[tex]3^{x+1}=15[/tex]
Let logarithm function both side,
[tex]\log3^{x+1}=\log15[/tex]
[tex](x+1)\log3=\log15[/tex]
Divide by the [tex]\log 3[/tex] both the sides
[tex](x+1)=\dfrac{\log15}{\log3}[/tex]
[tex](x+1)=\log_315[/tex]
[tex](x+1)=2.465[/tex]
Subtract with 1 both the sides,
[tex]x=2.469743-1[/tex]
[tex]x=1.469743[/tex]
Thus the value x for the given function is 1.469743. Hence the option 3 is the correct option.
Learn more about the Change of the base rule here;
https://brainly.com/question/13501523