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The area of a rectangle is 63m^2 and the length of the rectangle is 11m more than twice the width. Find the length and width.

User Jsonras
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1 Answer

4 votes

Answer:

width = 3.5 m

length = 18 m

Explanation:

area = length x width

x is the width then length = 2x + 11

x(2x + 11) = 63

2x^2 + 11x - 63 = 0

The formula to solve a quadratic equation of the form ax^2 + bx + c = 0 is equal to x = [-b +/-√(b^2 - 4ac)]/2a

with a = 2

b = 11

c = -63

substitute in the formula

x = [-11 +/- √(11^2 - 4(2)(-63))]2(2)

x = [-11 +/- √(121 + 504)]/4

x = [-11 +/- √625]/4

x = (-11 +/- 25)/4

x1 = (-11 + 25)/4 = 14/4 = 3.5

x2 = (-11 - 25)/4 = -36/4 = -9

since width can't be a negative number, x is 3.5

length = 2x + 11 = 2(3.5) + 11 = 18

User Mindaugas
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