Average = Mean
To find the mean, add up the numbers and divide it by how many numbers there are.
So,

There are 5 numbers in total.

To do these types of division, ignore the decimal and add a 0 at the end.
So we can do:

And put back the decimal.
Hope this helps :)
Answer:
(a - b)^2 = 49 - 4b^2 +2ab
Step-by-step explanation:
Given: a^2 + b^2 = 7b (assuming A is really “a”)
b^2 + (2b - a)^2 = 7^2
Find; (a - b)^2
Plan: Use Algebraic Manipulation
Start with b^2 + (2b - a)^2 = 7^2 =>
b^2 + 4b^2 - 4ab + a^2 = 49 by expanding the binomial.
a^2 + b^2 + 4b^2 - 4ab = 49 rearranging terms
a^2 + b^2 -2ab - 2ab + 4b^2 = 49 =>
a^2 - 2ab + b^2 = 49 - 4b^2 +2ab rearranging and subtracting 4b^2 and adding 2ab to both sides of the equation and by factoring a^2 - 2ab + b^2
(a - b)^2 = 49 - 4b^2 +2ab
Double Check: recalculated ✅ ✅
(a - b)^2 = 49 - 4b^2 +2ab
Answer:
b = 7√3
Step-by-step explanation:
This 30°- 60°- 90° triangle has the proportions:
side opposite of the 30° angle = x
side opposite of the 60° angle = x√3
side opposite of the 90° angle = 2x
____________________________
Given the side opposite of the 30° angle which is 7 units long, this can be thought of as x. Knowing the proportions of the other sides, we can find b knowing that this is the side opposite of the 60° angle which is x√3.
Since x = 7, x√3 = 7√3, and therefore
b = 7√3.
The "mean" is the "average" you're used to, where you add up all the numbers and then divide by the number of numbers.