If you do 50 times 4 it’s easier to find 500 times 400 because all you have to do it add 3 more zeros behind 200 making the answer be 200,000.
Answer: Option C)1 over 15 minus 1 over x equals 1 over 20
Explanation:
Since, Micah can fill a box with books in 15 minutes.
Therefore, the work done by Micah in one minute= 1/15
Also, Sydney takes the books out puts them on a shelf.
And the times taken by Micah when Sydney is also taking the books outside from the self= 20 minutes
Therefore, the work done by Micah in one minute when Sydney taking books out of the box= 1/20
Let Sydney alone takes x minutes to take books outsides the shelf.
Then, work done by Sydney in one minute=1/x
Thus, the work done by Sydney( by taking books out of the box)= the work done by Micah - work done by Micah and Sydney simultaneously= 1/15-1/20
⇒1/x=1/15-1/20
⇒1/15-1/20=1/x
⇒1/15-1/x=1/20 is the required expression.
Therefore, Option C is correct.
Look at the picture.

The base of the ladder is 6.47 feet from the house.
It is the most critical part in algorithm. This is to sort or arrange things or numbers in specific characteristics. This is to make things easier when you will be calculating and you can differentiate the results and your variable being considered in solving the problem.
Step-by-step explanation:
I am not sure what exactly you mean.
do you mean the complete square of an expression or
term ?
if so, then by multiplying this term by itself, and that means in general, every part is multiplied by every part and the part results are added considering the signs involved.
e.g.
squaring a+b
(a+b)(a+b) = a×a + a×b + b×a + b×b = a² + 2ab + b²
remember that multiplication and addition are commutative (you can flip the right and left sides with each other and still get the same result : a+b = b+a, a×b = b×a).
squaring a-b
(a-b)(a-b) = a×a + a×-b + -b×a + -b×-b = a² - 2ab + b²
remember that
+×- = -×+ = -
-×- = +
+×+ = +
a more complex example ?
squaring a-b+c
(a-b+c)(a-b+c) =
= a×a + a×-b + a×c + -b×a + -b×-b + -b×c + c×a + c×-b + c×c =
= a² - 2ab - 2bc + 2ac + b² + c²