A rectangular garden has dimensions 20 ft by 30 ft. a walkway will be added . the garden plus walkway is 336 sq ft larger than before, how wide is the walkway?

Question

solve algebraically. set up equation. 

Answer 1

Let x = width of the walkway

 

Dimensions of garden and walkway is 20+2x and 30+2x  find area:

 

(20+2x)(30+2x)-(20)(30) = 336  and solve for x

 

100x + 4x² = 336

 

25x + x² = 84

 

x² + 25x - 84 = 0

 

(x+28)(x-3) = 0

 

x is 3 (x cannot be -28)