Answer:

Step-by-step explanation:
<h2>Algebraic expressions</h2>
Difference: should be subtract.
N: should be a number.
Sum: Add
Therefore, the correct answer is 10-N=8+N.
Hope this helps!
Answer:
Hello!!! Princess Sakura here ^^
Step-by-step explanation:
The 1st one is:

The 2nd one is:

10 slices = 100%
Each of three people had 3 slices; 3 * 3 = 9
9 slices = 90%
Sally and her two friends ate 90% of the pizza.
Hope this helps.