Question

计算下列各题：

①(-4x³y²)³·(-4x²y³)² ÷(-2x的4次方y的4次方);
②(a-3b)²-(3a-b)²;
③(-3x的4次方y²+2x²y-1/4x³y²)÷(-2x)².

Answer 1

1. (-4x³y²)³·(-4x²y³)² /(-2x^4·y^4)
   

   =8x^(3*3+2*2-4)·y^(2*3+3*2-4)

   =8x^9·y^8

2. (a-3b)²-(3a-b)²
   

   =[(a-3b)+(3a-b)][(a-3b)-(3a-b)]

   =(4a-4b)(-2a-2b)

   =-8(a-b)²=-8a²+16ab-8b²

3. (-3x^4y²+2x²y-1/4x³y²)÷(-2x)²
   

   =(x²y)(-3x²y+2-1/4xy)÷(4x²)

   =(1/4)y(-3x²y+2-1/4xy)

Answer 2

①(-4x³y²)³·(-4x²y³)² ÷(-2x的4次方y的4次方);
=-2^6X^9Y^6×2^4X^4Y^6÷（-2X^4Y^4)
=32X^9Y^8
②(a-3b)²-(3a-b)²;
=[(a-3b)-(3a-b)][(a-3b)+(3a-b)]
=[-2A-2B][4A-4B]
=-8(A^2-B^2)
=8B^2-8A^2
③(-3x的4次方y²+2x²y-1/4x³y²)÷(-2x)².
=-3/4y²+1/2y-1/16xy²