Answer:
(x+a) (x+b)=x(x+b)+a(x+b)=x²+bx+ax+ab=x²+x(a+b)+ab
Scientific notation uses expression which gives easy access of order. The scientific notation of given number is: Option A: 1.6E-8
<h3>How to convert a number to scientific notation?</h3>
It is usually of the form
exponent of 10 starts)
(we have 1 ≤ |a| < 10 ) (where |a| is magnitude of a without sign)
This notation is used to get some idea of how large or small a number is in terms of power of 10.
<h3>What are some basic properties of exponentiation?</h3>
If we have
then 'a' is called base and 'b' is called power or exponent and we call it "a is raised to the power b" (this statement might change from text to text slightly).
Exponentiation(the process of raising some number to some power) have some basic rules as:

The given number is converted in scientific notation as:

Thus, the scientific notation of given number is: Option A: 1.6E-8
Learn more about scientific notation here:
brainly.com/question/3112062
It is 1
Explanation
[2(-5)-1]+10
[-10-1]+10
-11+10
=1
You are not right on #46. Since he is going 50 miles in 50 minutes, that means that he is going a mile a minute. That means in an hour, he will have gone 60 miles. That means he will have been going 60 mph, so the correct answer is (4)
I cannot help you with 47 because you did not include the picture it shows.