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:
7. 20 + 5 + 3/10 + 6/100
8. 7 + 4/10 + 2/100 + 5/1000
Step-by-step explanation:
We are writing two numbers in expanded form, to help, we can use the guide above both numbers. Expanded form is all about breaking apart a number by place value and putting them in an additional sequence.
Let's look at 7, 25.36.
There are the tens, ones, tenths, and hundredths place being used, therefore :
20 + 5 + 3/10 + 6/100
We can do the same for 8, 7.425.
There are ones, tenths, hundredths, and thousandths being used, therefore :
7 + 4/10 + 2/100 + 5/1000
4n - 8 = n + 13
4n - n = 13 + 8
3n = 21
n = 21/3
n = 7....the number(n) = 7