Answer:
15Step-by-step explanation:y = family members = 7x = cos
Step-by-step explanation:
THE ANSER is commutative property of addition
Answer:
33, 9
Step-by-step explanation:
I33-21I=12
I9-21I=
I-12I=12
Every SUM of an absolute value will always be positive!!
1 step: 
,

, then

.
2 step: 
, then




and

will have form

.
3 step: Solve this system

and dividing first equation on second we obtain

. So,

and

,

- the common ratio.
4 step: Insert

into equation

and obtain

, from where

.