Solve the Proportion $$\frac { x } { 21 } = \frac { 2 } { x + 1 }$$

Multiple Choice

Solve the proportion. $$\frac { x } { 21 } = \frac { 2 } { x + 1 }$$

A) $\quad x _ { 1 } = - 7 , x _ { 2 } = - 6$
B) $\quad x _ { 1 } = - 7 , x _ { 2 } = 6$
C) $\quad x _ { 1 } = 7 , x _ { 2 } = 6$
D) $\quad x _ { 1 } = 7 , x _ { 2 } = - 6$
E) no solutions