Find $\frac { d y } { d x }$ If $y = \frac { 1 } { 7 u - 1 }$

Short Answer

Find $\frac { d y } { d x }$ if $y = \frac { 1 } { 7 u - 1 }$ and $u = \frac { 1 } { x + 3 }$ .