If $\frac{a+1}{a^2-1} = \frac{1}{5}$, then the value of $a$ is -
We are given the equation: $ \frac{a+1}{a^2-1} = \frac{1}{5} $ Our objective is to determine the value of the variable $a$.
First, simplify the denominator $a^2-1$. This is a difference of squares, which factors as:
$ a^2-1 = (a-1)(a+1) $Substitute this factorization back into the original equation:
$ \frac{a+1}{(a-1)(a+1)} = \frac{1}{5} $Provided that $a \neq -1$ (which means $a+1 \neq 0$), we can cancel the $(a+1)$ term from both the numerator and the denominator:
$ \frac{1}{a-1} = \frac{1}{5} $This simplified equation implies that the denominators must be equal:
$ a-1 = 5 $To find the value of $a$, add 1 to both sides of the equation:
$ a = 5 + 1 $ $ a = 6 $We must verify our assumption that $a \neq -1$. Since $a=6$, the condition $6 \neq -1$ holds true, confirming the validity of the cancellation step.
Thus, the calculated value of $a$ is 6.