Answer:
w=4
Step-by-step explanation:
18+3w=30
3w=30-18
3w=12
w=4
It should be a positive 5 not a negative so the error was made at the end because u divide
Answer:

Step-by-step explanation:



You finish the leftover.
Answer:
No
Step-by-step explanation:
Rational numbers are those that can be represented in a fraction form.
2.12359.... cannot be represented in a fraction form.
So, it is NOT a rational number
See the attached picture: