-9
There are the same signs so you'd just add them together and use whatever sign they are..
Answer:
10.91%
Step-by-step explanation:
Take your number: 10.9091
Now find the first 3 decimals: 10.<u>909</u>
If the last (3rd) decimal is 5 or more raise the 2nd decimal: 10.9<u>09</u> → 10.9<u>1</u>
That is 2 decimal places
(if your teacher doesn't want it rounded then just 10.90%)
Answer:

Step-by-step explanation:
Given the equation of the circle: 
We wish to express it in a Standard form:
We begin by re-arranging:

Next, divide the coefficient of x by 2, square it and add it to both sides.
Do the same for y.

Next, we factorize

This is the standard form.