Verified Answer :

bshawy89

2+4z-18 
change it so it's an equation
2+4z-18=0
then get 4z alone on one side by subtracting 4z from both sides
2-18=-4z
-16= -4z
divide both sides by -4

a negative divided by a negative becomes positive
4 =z
plug it in
2+4(4)-18
4x4 is 16
2+16-18=0
0=0

the same can be done for the second one 2+k-8

make it 2+k-8=0

move the k to get it alone so subtract k from both sides

2-8=-1k

-6 = -1K

you can divide by K to make K=6 

plug in 2+6-8=0

0=0