-3x²y³×(x²-1)-(x²+1)×5x²y³

-3x²y³×(x²-1)-(x²+1)×5x²y³
-3x²y³×(x²-1)-(x²+1)×5x²y³

-3x²y³×(x²-1)-(x²+1)×5x²y³
-3x²y³×(x²-1)-(x²+1)×5x²y³
= [-3×(x²-1)-(x²+1)×5]x²y³
=(-8x²-2)x²y³
=-8x⁴y³-2x²y³

【解】－3x²y³×(x²－1)－(x²＋1)×5x²y³
==－3x＾4y³＋3x²y³－5x＾4y³＋5x²y³
==－7x＾4y³＋8x²y³

-3x²y³×(x²-1)-(x²+1)×5x²y³
= [-3×(x²-1)-(x²+1)×5]x²y³
=[-3x²+3-5x²-5]
=(-8x²-2)x²y³
=-8x⁴y³-2x²y³