Step-by-step explanation:
We have

First, 125 is a perfect cube because

and
x^3 is a perfect cube because

so we can use the difference of cubes identity

Let say we have two perfect cubes:
64 because 8×8×8=64
and 27 because 3×3×3=27 and let subtract

we know that

but using the difference of cubes identity we should get the same thing.
Remeber cube root of 64 is 4 and cube root of 27 is 3 so we have


So the difference of cubes works for real numbers. This is a good way to help remeber the identity using real numbers.
Back on to the topic,
we know that 5 is cube root of 125 and x is the cube root of x^3 so we have


Answer:

Step-by-step explanation:
x + 7) x³ + 7x²- 2x + 6 ( x²- 2
<u> x³ + 7x²</u>
-2x + 6
<u>-2x - 14</u>
+20
Therefore, we can write the expression in the remainder quotient form as,

Answer:
2 21 degree angles
Step-by-step explanation:
An isosoles triangle has two congruent angles and every triangle's sum of interior angles equals 180 degrees. 138*2>180, so the 138 degree angle cannot be congruent to any of the other angles. Therefore:
180=138+2x
42=2x
21 degrees=x
Draw the number line then put the numbers on the number line by twos. Fore example, 2-4-6-8-10
Answer: 
Step-by-step explanation:
We have several properties of exponents in use here. The two that are used are:
<em>(Exponents with the same base that are being multiplied together can have the exponents added)</em>
<em>(A base raised to a power, and then raised to another power means that you can multiply the exponents to get the same result as doing inside operations and then outside operations)</em>
<em />
Let's apply it!
First, let's simplify what's inside the parenthesis.
<em>(Remember, they have the same base of "x", so we can add the exponents)</em>
=
= 
Now we have
. Let's use the second rule.
= 
Hope this helps! :^)