Answer:
1. option B is correct i.e., 
2. option D is correct i.e.,
.
3. option B is correct i.e.,
.
Step-by-step explanation:
1. Since the given equation is:

As we know that 
So, the given equation can be represented as:

2. Given equation is:

As we know that 
so the given equation can be represented as:
.
3. Given equation is:

by using the properties
,
and 

= 
= 
= 
= 
=
.
which is option B.
Hey there!
x^2 + y^2
= 7^2 + 5^2
= 7 * 7 + 5 * 5
= 49 + 25
= 74
Therefore, your answer should be: 74
Good luck on your assignment & enjoy your day!
~Amphitrite1040:)
Answer:
It should be 92
Step-by-step explanation:
The mean is 52 because 42+45+58+63=208 then you divide it by the amount of numbers: 4 : 208 divided by 4= 52