simplify Boolean expression minimuum literal mano 2.4 b

Question

(x'y' + z)' + z + xy + wz

Answer 1

((x'y')' . z' ) + z + xy + wz

((x+y) . z') + z + xy + wz

xz' + yz' + z +xy + wz

xz' + yz' + xy + z(1+w)

xz' + yz' + xy + z

(x + y)z' + z + xy

(z + z') . (z+ (x+ y)) + xy

z + x + y + xy

x + y + z 

Comments

Can u pls explain this step bit more:

From (x + y)z' + z + xy

To (z + z') . (z+ (x+ y)) + xy

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what is x + yz = (x + y)(x + z)

so z + z'(x + y) = (z = z')( z + x+ y)