A rectangular garden is 8 ft longer than it is wide. Its area is 609 ft2. What are its dimensions?

Question

Needing length and width. How do I get there?

Answer 1

L=8+W

LW = 609

(8+W)W = 609

W^2 +8W -609 = 0

use the quadratic equation, complete the square or factor if possible

(W-21)(W+29) = 0

W =21 feet, L=29 feet

W=-8/2 +/-(1/2)sqr(8^2 +4(609)

or complete the square

W^2 +8W +16 = 609+16 = 625

(W+4)^2 = 25^2

W = -4 +/-25

W = 21 or -29

L = 29 or -21

generally ignore the negative solutions

Length =29 feet, Width =21 feet