You have a lot of questions here, I can help you with a few of them.
When you simplify the polynomials, you put together all of the terms that have the same degree. That means the variables have the same exponents. The number of terms are the items separated by plus and minus signs.
Here are the answers for the first three:
1)

2)

3)
Answer:
It approximately dropped 0.027777 per hour.
Step-by-step explanation:
First, we calculate the decrease.
Decrease = 11/40 = 0.275
Then, we calculate the time interval.
From 10 pm to 7:54 hours will be 9.54 hours
Time interval= (9 + 54/60) hours
Time interval=9.9 hours
Finally, we calculate how much it dropped each hour
0.275/9.9 ≈ 0.027777
So it approximately dropped 0.027777 per hour.
Step-by-step explanation:
K=4
I think so
have a great day ahead
If you need to, you can write and solve an equation for the factor you seek.
... 6×10^10 = factor × 2×10^-3
Divide by 2×10^-3 to find the value of the factor:
... (6×10^10)/(2×10^-3) = factor
... factor = (6/2)×10^(10-(-3))
... factor = 3×10^13
The first number is 3×10^13 times the second number.
_____
An exponent signifies repeated multiplication.
... 10×10×10 = 10³
Just as you cancel common factors when you do division, you can subtract exponents.

The same process works regardless of the signs of the exponents. When multiplying, we add exponents; when dividing we subtract the exponent of the denominator.
Answer:
<em>My friend Matthew bought </em><em>four</em><em> pizzas. We ate five eighths of each pizza leaving </em><em>three eighths</em><em> left in each box. How much pizza did we have left over between the four boxes?</em>
<em> 4 times 3/8 is equal to 1.5. (just felt it was incomplete without this answer. Also, hope this was a satisfactory answer.)</em>