七年级数学!计算（a²-2a）²+2（a²-2a）+1 4x²y²-（x²+y²）² 34.5²+69×65.5+65.5²

2019-06-02

七年级数学!

计算

（a²-2a）²+2（a²-2a）+1 4x²y²-（x²+y²）² 34.5²+69×65.5+65.5²

优质解答

解（ a²-2a）²+2（a²-2a）+1
=(a²-2a+1)²
=(a-1)^4
4x²y²-（x²+y²）²
=（2xy-x²-y²)(2xy+x²+y²)
=-(x-y)²(x+y)²
34.5²+69×65.5+65.5²
=34.5²+2×34.5×65.5+65.5²
=(34.5+65.5)²
=10000 解（ a²-2a）²+2（a²-2a）+1
=(a²-2a+1)²
=(a-1)^4
4x²y²-（x²+y²）²
=（2xy-x²-y²)(2xy+x²+y²)
=-(x-y)²(x+y)²
34.5²+69×65.5+65.5²
=34.5²+2×34.5×65.5+65.5²
=(34.5+65.5)²
=10000