Respuesta :

Let the width be x 

Length= x+7 

Area=lw 

99=(x+7)(x) 
99=x²+7x 
0=x²+7x-99 
x= -14.04 or x=7.04

Since a length cannot be negative, the width is 7.04 ft and the length (7.04+7)=14.07 ft

Hope I helped :)