Stuck on boolean algebra problem

Question

Could someone please explain me why

$x.y+x.z+y'.z$

Is equal to

$x.y+y'.z$?

I just can't simplificate it..

Answer 1

$x.y+x.z+y'.z$

$=x.y+x.z.1+y'z$ [as,$a.1=a$]

$=x.y+x.z.(y+y')+y'z$ [as $(a+a')=1$]

$=x.y+x.z.y+x.z.y'+y'z$

$=x.y(1+z)+y'z(x+1)$

$=(x.y+y'z)$ [as $(a+1)=1$]

Hope you got your answer.