计算:
(1)a2•(﹣a4)+2(a2)3
(2)(2x﹣1)(2x+1)﹣(x﹣6)(4x+3)
(3)(2x﹣3y)2+2(y+3x)(3x﹣y)
(4)(a﹣2b+3)(a+2b+3)
(5)
(6)(2m+3n)(2m﹣n)﹣2n(2m﹣n)
(1)a2•(﹣a4)+2(a2)3
(2)(2x﹣1)(2x+1)﹣(x﹣6)(4x+3)
(3)(2x﹣3y)2+2(y+3x)(3x﹣y)
(4)(a﹣2b+3)(a+2b+3)
(5)

(6)(2m+3n)(2m﹣n)﹣2n(2m﹣n)
下列计算正确的是( )
A.(x+y)2=x2+y2 | B.(x﹣y)2=x2﹣2xy﹣y2 |
C.(x+1)(x﹣1)=x2﹣1 | D.(x﹣1)2=x2﹣1 |