<PRE><B>Question 176404</B>
I need help putting 25x^2+16y^2+150x=160y-225 in standard form and then finding the a^2 value. 
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Complete the square on the x-terms and on the y-terms:

25(x^2 + 6x + ?) + 16(y^2 - 10y + ?) = -225
25(x^2 + 6x + 9) + 16(y^2 - 10y + 25) = -225 + 25*9 + 16*25
25(x+3)^2 + 16(y-5)^2 = 400
[(x+3)^2]/16 + [(y-5)^2]/25 = 1
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a^2 = 25
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Cheers,
Stan H.
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