The forth one is correct hope this helps :)))
Answer:
22 people
Step-by-step explanation:
(n*3)+6-(n*2)=n+3
3n+6-2n=n+3
3n-2n-n=3-6 every n on the left and free numbers on the right
0=-3
contradiction, there are no solution
Answer:
it should be -2/5 or 
Step-by-step explanation:
Answer:
It appears to be substitution
Step-by-step explanation:
I think you are talking about system of equations