Pls help this is for a Unit test because I really don't understand this.

x+y=90

x=30-y=x

step-by-step explanation:

if you understand you will get the answer

2

step-by-step explanation:

vvvvv

step-by-step explanation:

if u want da anser kill your teeser ifu hav wun

answer 1 : option "c"

answer 2 : option "d"

answer 3 : option "b"

answer 4 : option "d"

answer 5 : option "b"

answer 6 : option "a"

answer 7 : option "c"

answer 8 : option "d"

answer 9 : option "c"

answer 10 : option "d"

answer 11 : option "c"

answer 12 option "b"

answer 13 option "c"

answer 14 option "c"

answer 15 option "d"

answer 16 option "a"

answer 17 option "b"

answer 18 option "c"

answer 19 option "a"

answer 20 option "a"

answer 21 option "c"

d