1) ( 0.75X - 0.25Y )^2
( 0.75 * 16 - 0.25 * ( - 16 )) ^2 = (12 + 4 )^ 2 = 16 ^ 2 = 256
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2) ( 0.25X + 0.75Y) ^2
( 0.25 * 16 + 0.75 * ( -16 ))^2 = ( 4 - 12 )^2 = ( - 8 )^2 = 64
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3) 256 - 64 = 192