2（4t-1)的平方+5（4t-1)-3

2（4t-1)²+5（4t-1)-3
=[2(4t-1)-1][(4t-1)+3]
=(8t-2-1)(4t-1+3)
=(8t-3)(4t+2)
=2(8t-3)(2t+1)
x²+2xy+y²-3x-3y-4
=(x+y)²-3(x+y)-4
=[(x+y)-4][(x+y)+1]
=(x+y-4)(x+y+1)
a²+a-2-(a-1)
=(a+2)(a-1)-(a-1)
=(a-1)(a+2-1)
=(a-1)(a+1)
(x²+4x）²-2b(x²+4x）+105这道题有问题,没法分解.