SOLUTION: the length of a photograph is 8 cm more than its width. It has an area of 20cm2. Write an equation and solve to find the dimensions of the photograph

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: the length of a photograph is 8 cm more than its width. It has an area of 20cm2. Write an equation and solve to find the dimensions of the photograph      Log On


   



Question 925928: the length of a photograph is 8 cm more than its width. It has an area of 20cm2. Write an equation and solve to find the dimensions of the photograph
Answer by TimothyLamb(4379) About Me  (Show Source):
You can put this solution on YOUR website!
L = w + 8
Lw = 20
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(w + 8)w = 20
ww + 8w - 20 = 0
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the above quadratic equation is in standard form, with a=1, b=8 and c=-20
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to solve the quadratic equation, by using the quadratic formula, copy and paste this:
1 8 -20
into this solver: https://sooeet.com/math/quadratic-equation-solver.php
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the quadratic has two real roots at:
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w = 2
w = -10
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the negative root doesn't fit the problem statement, so use the positive root:
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answer:
w = 2 cm
L = 10 cm
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