Question

[(3x2y?2xy2)(x2y?2xy2)?(?3xy2)2]÷(?12x2y2

[(3x2y?2xy2)(x2y?2xy2)?(?3xy2)2]÷(?12x2y2)

Answer 1

原式=（3x⁴y²-6x³y³-2x³y³+4x²y⁴-9x²y⁴）÷（-

1

2

x²y²），
=（3x⁴y²-8x³y³-5x²y⁴）÷（-

1

2

x²y²），
=-6x²+16xy+10y²．