A rectangular deck is 12ft by 14ft. When the length and width are increased by the same amount, the area becomes 288sq. ft. By how much were the dimensions increased?

Respuesta :

Dimensions of rectangle = 12 + x and 14 + x

(12 + x) (14 + x) = 288

 x^2 + 26x + 168 = 288

 x^2 + 26x - 120 = 0


(x + 30) (x - 4) = 0

x=-30, x =4

 since 4 is positive

 the dimensions increased by 4 feet

check the answer

12+4 = 16

14 +4 = 18

18*16 =288

 


its 16 by 18 so by 4 ft