# boolean algebra help

#### devin sierra

Joined Sep 22, 2014
6
ok i have a few problems i need help with

1) prove ::: xy+yz+xz = xy + xz
doing the left side :: i factored out z --> xy+ z(y+x) .. no idea where to go from there

2) prove (x+y)(x+z) = xz+xy
foil to get 0+xz+xy+yz then factor --> z(x+y)+(x`y) then unsure again

for some reason i understand calculus more than i do this lol... I dont want the answer but is there a boolean rule im missing or not applying? or any guidance.. thanks

#### shteii01

Joined Feb 19, 2010
4,644

#### devin sierra

Joined Sep 22, 2014
6
ya i have a list of these but i cant figure out how to manipulate the equation

#### dalam

Joined Aug 9, 2014
58
For first multiply both sides by X.
xy+xyz+0=xy+0
xy(1+z)=xy
xy=xy QED
Do the same for second question.