1/3 is the same as 3/9. To solve this, subtract 3/9 from 7/9.

Your answer is
What's happening is that every subtraction can be written as "addition of the opposite."
18-5 = 18 + (-5)
One reason this is done in the work you showed is that they're trying to show why you distribute the negative and the 1 into the parentheses, why you multiply everything in the parentheses by "-1" and not just 1.
The other reason is to later to be able to move the individual terms around, so you'll be able to combine like terms.
When you move terms around, the sign has to stay attached to the term, so writing all the subtractions as addition helps keep the sign attached.
Answer:
8n^2 8n squared
Step-by-step explanation:
-8 - 5n = 64 + 3n
+5n +5n add 5n to both sides, 5n's cancel out on the left.
______________
-8 = 64 + 8n
-64 -64 subtract 64 on both sides, 64's cancel out on the right.
______________
-72 = 8n
___ ___ divide 8 on both sides, 8's cancel out from the right.
8 8
n= -9, final answer
Answer: 12πins.
Step-by-step explanation:
Since the area if a circle = πr²
From the question
Area of the circle = 36πins²
To find the circumference of the circle, we need to find the common radius of the circle and this could be achieved from the area of the circle given above.
πr² = 36π, solving this gives. Divide through by π
r² = 36
r = +/-√36
= +/-6
Now to find the circumference of the circle, we substitute for r in the formula below.
Circumstances = 2πr
= 2 ×π × 6
= 12πins.