Answer:

Step-by-step explanation:

Second equation times 3:

1st equation minus equation above:

Insert to equation:

Need more information. You said which of the following and didn't put any questions under it
Answer:
9
Step-by-step explanation:
equation: QRI+IRS=QRS
calculate it and you get x=9
Answer:
I really don't know but can u help with mine-_-
Answer:
the set of elements that are common to each of the given sets
Step-by-step explanation: