A garden is in the shape of a rectange. One side of the garden has 20 ft ength the other has a length of x. You pan to build a sidewalk of wdth 4 ft to surrond the garde . The cost to dig and pour concrete is $88 per sq ft. Exoress the cost to buid the sidewallk as a function of x.

1 answer

outside dimensions = 28 by (x+8)
garden dimensions = 20 by x

concrete area = 28(x+8) - 20 x
= 8 x + 224

cost = 88 (8 x + 224) = 704 x + 19712