5a+3b
5(2)+3(4)
10+12
22
(5+a)(3+b)
(5+2)(3+4)
(7)(7)
49
The order of the steps differ for the two expressions because for the first expression, you multiply 5a and 3b first. Then, you add them together. However, for the second expression, you add what's inside the parenthesis first then multiply them. So, the order of the steps is the opposite of the other expression.
Answer:

Step-by-step explanation:
Given: 76,45,64,80,92
Required: Determine the standard deviation
We start by calculating the mean

Where x-> 76,45,64,80,92 and n = 5



Subtract Mean (71.4) from each of the given data

Determine the absolute value of the above result

Square Individual Result

Calculate the mean of the above result to give the variance


Hence, Variance = 255.298
Standard Deviation is calculated by 


