1. $\frac { 1 } { x } + \frac { 5 } { 4 x } = \frac { 1 } { x + 1 }$

   Hint (a):

   Multiply by the common denominator $4x\left(x + 1\right)$ to remove the fractions.

   Answer (a):

   $x = −1.8$

Challenge: $\frac { 1 } { 1 - x } + \frac { 1 } { 1 + \sqrt { x } } = \frac { 1 } { 1 - \sqrt { x } }$