Find the LCD $$\frac { 9 } { x } , \frac { 4 } { x + 1 }$$

Multiple Choice

Find the LCD. Do not combine fractions.
- $$\frac { 9 } { x } , \frac { 4 } { x + 1 }$$

A) $x$
B) 36
C) $x + 1$
D) $x ( x + 1 )$