Answer:
We use scientific notation as sometimes numbers are so so big, that it becomes inconvenient for us to write the actual number.
Step-by-step explanation:
For example, if you have 9 billion of something, you wouldn't want to write those 9 zeroes all the time.
When writing in scientific notation we count the number of decimal places to when we have one non-zero integer to the right of the decimal place. We then write that number and multiply it by ten to the number of decimal places you counted earlier.
e.g. 4.8 X 10^7
Answer:
D)
9 units
Step-by-step explanation:

-9+x ?
I don’t know if this is the right answer
Answer:
B
Step-by-step explanation:
Given
P = 2(l + b) ← distribute
P = 2l + 2b ( subtract 2b from both sides )
P - 2b = 2l ( divide both sides by 2 )
= l → B