另一个多项式
=(M²-1)-(3M²-2M+1)/2
=-M²/2+M-3/2
B-2A
=3-2X²+X-2(2X²-1)
=3-2X²+X-4X²+2
=-6X²+X+5
(5X²-3Y²)-3(X²-Y²)-(-Y²)
=5X²-3Y²-3X²+3Y²+Y²
=2X²+Y²
=2*25+9
=59
另一个多项式
=(M²-1)-(3M²-2M+1)/2
=-M²/2+M-3/2
B-2A
=3-2X²+X-2(2X²-1)
=3-2X²+X-4X²+2
=-6X²+X+5
(5X²-3Y²)-3(X²-Y²)-(-Y²)
=5X²-3Y²-3X²+3Y²+Y²
=2X²+Y²
=2*25+9
=59