Question

初二计算

（-a)²×(a²)²+3a×a的五次
(-m×n²)³+(2mn)³×n³
(-4a³+12a²b-7a³b²)÷(-4a²)
(3mn+2)(2mn-3)
(2x-1)(x+½)(x²+¼)
[(a+5b)²-(a-5b)²]÷(-5b)
[(x-y)²+(x+y)(x-y)]÷2x

Answer 1

（-a)²×(a²)²+3a×a的五次
=a²×a的4次方+3a的6次方
=a的6次方+3a的6次方
=4a的6次方(-m×n²)³+(2mn)³×n³
=-m³n的6次方+8m³n³×n³
=-m³n的6次方+8m³n的6次方
=7m³n的6次方
(-4a³+12a²b-7a³b²)÷(-4a²)
=a-3b+7ab²/4(3mn+2)(2mn-3)
=3m²n²-9mn+4mn-6
=3m²n²-5mn-6(2x-1)(x+½)(x²+¼)
=2(x-1/2)(x+1/2)(x²+1/4)
=2(x²-1/4)(x²+1/4)
=2(x的4次方-1/16)
=2x的4次方-1/8[(a+5b)²-(a-5b)²]÷(-5b)
=(a²+10ab+25b²-a²+10ab-25b²)÷(-5b)
=20ab÷(-5b)
=-4a[(x-y)²+(x+y)(x-y)]÷2x
=(x-y)(x-y+x+y)÷2x
=x-y