Let's assume the number be x.
So, sum of a number and 10 can be written as x+10.
Now the given statement is "One half of the sum of a number and 10 ".
So, one half of x+10 can be written as 
Answer:
A
Step-by-step explanation:
expanding the bracket, we would have
-2x -18 = -x+1+2
-2x+x= 3 +18
-x=21
x=-21
Answer:
6
Step-by-step explanation:
Firstly, this is the pythagoreans theorem a^2+b^2=c^2
Now that we know that, we will solve for x.
(x+2)^2+x^2=100 ( The 100 is just 10 squared )
Finally, you solve for x and get 6.