4. all of the following are functions of the skin except
2) protection
b) vitamin d synthesis
c) movement
d) temperature regulation
e) sensation

try using substitution:

x + y - 6 = x - y. (i'm not giving you the exact answer). since 0 = x - y, then sub 0 in the equation with x - y. combine your like terms, and then use inverse operations, and you'll have your answer.

: -)

but there is no

i guess you forgot putting it.