Adding and subtracting big polynomials like these are pretty easy. You just need to combine like terms. For example:
1.)

2.)


(The 3x^2 and the 2 stay intact while the 5xy and 7xy combine together)
All you have to do is combine the numbers that have the same powers of x and y with each other. x^2 will combine with x^2 and xy^2 wil combine with xy^2 exc. If there is no other number with the same x and y's, then you just leave it as it is in the answer.
Now with the original question, I see a -9xy^3, and thats gonna combine with the 3xy^3 in the second polynomial and the 2xy^3 in the third one.

So far we have -4xy^3, the next term is going to be a -9x^4y^3, and that's gonna combine with the 3x^4y^3 in the third one.

We now finished adding the like terms that were in the first polynomial, we will move onto the second polynomial. The first term in this one is 3xy^3, in which we already added in the first step. At this point, it doesn't look like there are any other terms that have the same x and y behind them. So we can move on and write the final answer:

(All on the same line of course)
Also, for your second question, the order does not matter in which you write the terms. I could write the 7y^4 behind the -8x^4y^4 and it would still be the same answer.
If you have any other questions let me know :) while I double check my work.
 
        
             
        
        
        
Answer:
The constant term in the polynomial is 140 and it represents the revenue when the price is not increased.
Step-by-step explanation:
To find: What is the constant term in the polynomial expression, and what does it represent?
The given expression is  .
.
To find the constant term we can simply put x=0 in the given equation where x represents the number of $1 increase in price.
=
=
The constant term is 140 and it represents the revenue when the cost of a hot dog is $2.
Hence, the constant term in the polynomial is 140 and it represents the revenue when the price is not increased.
 
        
             
        
        
        
Is it cheaper then without it? If so you should
        
             
        
        
        
Answer:
In a linear equation  of one variable there are two terms terms containing variable and constant.
Variable means term containing x,y,z which act as variables. and constant means any rational number . In higher classes you can include real number also.
The given equation is 3x + 5x = 10 
 So, the solution out of four options is A) 5x = 20.
 Here variable is on one side of equation and constant on other side.
But Option (D) looks absolutely correct if we replace ? by either + sign or Negative (-) sign.
 
        
                    
             
        
        
        
Answer:
70
Step-by-step explanation:
RU=20 (45-45-90 triangle)
use pythagorean theorum
20^2+b^2=73^2
evaluate
b^2=4929
sq root both side
rounded to nearest integer, side SU is 70