Question 744486
1. Solve the following equations
a) log(base 2) x+1 + log(base 2) x-1 = 3
{{{log(2,(x+1))+log(2,(x-1))=3}}}
{{{log(2,(x+1)(x-1))=3}}}
{{{log(2,(x+1)(x-1))=log(2(8))}}}
(x+1)(x-1)=8
x^2-1=8
x^2=9
x=±3
..
b) log(base 2) x^2-1 =3 
{{{log(2,(x^2-1)) =3}}}
{{{log(2,(x^2-1)) =log(2(8))}}}
x^2-1=8
x^2=9
x=±3
..
c) explain why the equations log(base 2) x+1 + log(base 2) x-1 = 3 and log(base 2) x^2-1 =3 are not equal. 
The equations of a) and b) are equal as shown above.