MATHS-factorization!!STEPS!!

1.
16(2x+1)^2-(x+5)^2
=[4(2x+1)]^2-(x+5)^2
=[4(2x+1)-(x+5)][4(2x+1)+(x+5)]
=(7x-1)(9x+9)
=9(7x-1)(x+1)

2.
242xy-2xy(x+y)^2
=2xy[121-(x+y)^2]
=2xy[11^2-(x+y)^2]
=2xy[11-(x+y)][11+(x+y)]
=2xy(11-x-y)(11+x+y)

3.
6z^3-54z(x-y)^2
=6z[z^2-9(x-y)^2]
=6z[z^2-[3(x-y)]^2]
=6z[z-3(x-y)][z+3(x-y)]
=6z(z-3x+3y)(z+3x-3y)

4.
81h^2-16k^2+9h^2k+4hk^2
=(9h)^2-(4k)^2+hk(9h+4k)
=(9h-4k)(9h+4k)+hk(9h+4k)
=(9h+4k)(9h-4k+hk)

5.
256x^2-25y^2+15y-48x
=(16x)^2-(5y)^2+3(5y-16x)
=(16x-5y)(16x+5y)-3(16x-5y)
=(16x-5y)(16x+5y-3)