Use the grouping method to factor the polynomial below completely.
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Answer:
Step-by-step explanation:
Perimeter is
P = 2L + 2W. We are given the perimeter as 180 feet, so
180 = 2L + 2W. Solve this for either L or W. I chose W, no reason...
180 - 2L = 2W so
90 - L = W Hold that thought. We'll come back to it in a minute.
Area is
A = LW. We are given the area as 1800 square feet, so
1800 = LW. Sub in 90 - L for W:
1800 = L(90 - L). Distribute to get a quadratic:
Get everything on one side and solve for the length by factoring:
Factor this however you like to factor quadratics, to get the length of
L = 30 and L = 60. First off, the length is longer than the width in general, so if we want to solve for the width, plug in 60 as L in the equation in bold print:
90 - 60 = W and
30 = W
So L = 60 and W = 30