(3x方+5)(-3x方+5)-x方(7x+8)(7x-8)-(8x)方其中x=-2

(3x方+5)(-3x方+5)-x方(7x+8)(7x-8)-(8x)方其中x=-2

原式=25-9x^4-x²;(49x²;-64)-64x²;
=35-9x^4-49x^4+64x²;-64x²;
=-58x^4+35
=-928+35
=-893