How can expressions be written and evaluated to solve for unknowns in the real world?
Writing expressions requires figuring out which quantity in a situation is unknown, and define a variable to represent that quantitiy.
We look for words in the problem that will help us out what kind of operation to use in a given situation.
Example:
Donna bought 5 chocolate bars, and then ate some. Write an expression to represent how many chocolate bars Donna has left.
If we let the variable c represent the number of chocolates Donna has eaten, then we can write the expression on how many bars Donna has left as: 5 - c
Answer:

Step-by-step explanation:
So we have the function:

And we want to find the derivative using the limit process.
The definition of a derivative as a limit is:

Therefore, our derivative would be:

First of all, let's factor out a 4 from the numerator and place it in front of our limit:

Place the 4 in front:

Now, let's multiply everything by (√(x+h)(√(x))) to get rid of the fractions in the denominator. Therefore:

Distribute:

Simplify: For the first term on the left, the √(x+h) cancels. For the term on the right, the (√(x)) cancel. Thus:

Now, multiply both sides by the conjugate of the numerator. In other words, multiply by (√x + √(x+h)). Thus:

The numerator will use the difference of two squares. Thus:

Simplify the numerator:

Both the numerator and denominator have a h. Cancel them:

Now, substitute 0 for h. So:

Simplify:

(√x)(√x) is just x. (√x)+(√x) is just 2(√x). Therefore:

Multiply across:

Reduce. Change √x to x^(1/2). So:

Add the exponents:

And we're done!

Hecta is the prefix meaning 100 times;
Kilo means 1000 times;
Deca is one tenth;
and Centi is one hundredth.
In this case, the smallest and most suitable for measuring small objects would be Centi.
Answer:
6
Step-by-step explanation:
We can obtain the greatest common factor by listing the factors of the 2 numbers, that is
Factors of 18 are 1, 2, 3, 6, 9, 18
Factors of 42 are 1, 2, 3, 6, 7, 14, 21, 42
The common factors are 1, 2, 3, 6
The greatest common factor is 6