Integration over a region/(double integral, how to factor it) Urgent please

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SUMMARY

The discussion focuses on using a double integral to find the area of the region D defined by the inequality 4x² + 12xy + 13y² + 40y ≤ -75. The key method to solve this problem is completing the square, which transforms the expression into a recognizable form of a rotated ellipse. The user struggles with the algebraic manipulation, specifically arriving at the equation (2x + 3y)² + 4(y + 5)² = 25, indicating a need for clarity in the steps involved in completing the square without computational tools.

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  • Understanding of double integrals in calculus
  • Knowledge of completing the square technique in algebra
  • Familiarity with the properties of ellipses and their equations
  • Basic skills in manipulating quadratic expressions
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  • Study the method of completing the square for quadratic equations
  • Learn how to derive the area of an ellipse from its standard form
  • Explore the application of double integrals in calculating areas of non-standard shapes
  • Investigate the geometric interpretation of rotated conics
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Students studying calculus, particularly those focusing on double integrals and conic sections, as well as educators seeking to clarify the process of completing the square in algebraic contexts.

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Homework Statement


Use a double integral to find the area of the region D, where

D={(x,y) contained in R2 | 4x2+12xy+13y2+40y<=-75}

Hint: complete the square
I have a hard time getting the region, i should complete the square to get a formula in R2 that describes the region, i tried to do complete the square but it comes something like this:
(2x+3y)2 + 4(y+5)2=25

this does not make sense it look weird, i am not sure how to get this area. please help

The Attempt at a Solution


above
 
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yes i have tried that but, I am not suppose to use any calculators. just by hand there fore some how i must factor not sure how
 

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