来自邓达华的问题
一些数学计算题4(a²+1)²-16a²=?(2x-1)²-6(2x-1)+9=?9(m+2n)²-4(2m-n)²=?
一些数学计算题
4(a²+1)²-16a²=?
(2x-1)²-6(2x-1)+9=?
9(m+2n)²-4(2m-n)²=?
1回答
2020-05-22 22:09
一些数学计算题4(a²+1)²-16a²=?(2x-1)²-6(2x-1)+9=?9(m+2n)²-4(2m-n)²=?
一些数学计算题
4(a²+1)²-16a²=?
(2x-1)²-6(2x-1)+9=?
9(m+2n)²-4(2m-n)²=?
(a²+1)²-16a²
=(a^2+1+4a)(a^2+1-4a)
=[(a+2)^2-3][(a-2)^2-3]
(2x-1)²-6(2x-1)+9
=[(2x-1)-3]^2
(m+2n)²-4(2m-n)²
=[m+2n+4m-2n][m+2n-4m+2n]
=5m(4n-3m)
=20mn-15m^2