As there are 81 tiles total, that makes your area 81. Being a square, that makes your area equation A=s^2. As you need a side, this makes your equation s=√A. Plugging in 81 as A, we get s=√81=9, so an edge has 9 tiles.
Answer:

Step-by-step explanation:
When dividing 46 by 9 quotient is 5 and remainder is 46 - 45 = 1

Answer:
2.0
Step-by-step explanation:
Answer:
X=-1, y=4
Step-by-step explanation:

by using eliminating property

by substitution
X=-1