contestada

which of the following is equivalent to (3^x+1)(3^x-1)^2/9^x for all x? a. 3^2x-1 b. 3^x c. 3^x-1 d. 3^x-2 e. 3^3-x

Respuesta :

Answer:

[tex]3^{x-1}[/tex]

Explanation:

Given

[tex]\frac{(3^{x+1})(3^{x-1})^2}{9^x}[/tex]

Required

Find its equivalent

[tex]\frac{(3^{x+1})(3^{x-1})^2}{9^x}[/tex]

Expand the numerator

[tex]\frac{(3^{x+1})(3^{x-1})(3^{x-1})}{9^x}[/tex]

Apply law of indices: [tex]a^m * a^n = a^{m+n}[/tex]

This gives

[tex]\frac{3^{x+1+x-1+x-1}}{9^x}[/tex]

Collect like terms

[tex]\frac{3^{x+x+x+1-1-1}}{9^x}[/tex]

[tex]\frac{3^{3x-1}}{9^x}[/tex]

Express [tex]9^x[/tex] as a factor of 3

[tex]\frac{3^{3x-1}}{3^2^x}[/tex]

Apply law of indices: [tex]\frac{a^m}{a^n} = a^{m-n}[/tex]

This gives

[tex]3^{3x-1-2x}[/tex]

[tex]3^{3x-2x-1}[/tex]

[tex]3^{x-1}[/tex]

Hence,

[tex]\frac{(3^{x+1})(3^{x-1})^2}{9^x}[/tex] is equivalent to [tex]3^{x-1}[/tex]