He saves $200 (the amount of change over the original amount $500
200/500  = 2/5  and 2/5 = 40%  (divide 2 by 5 and get .4 which = 40%)
40% discount is the answer to your question
        
             
        
        
        
-2x^4 + 24x^2 - 10
u have 3 terms.....and since u are only dealing with 1 variable with the highest exponent being 4, then what u have here is a 4th degree trinomial.
U have a lead coefficient of -2.
Ur constant term is -10
And ur middle term (24x^2) has a degree of 2
a cubic binomial.....a binomial has 2 terms and it being cubic means the highest term has a degree of 3
example would be : x^3 - 4
how many constants can a polynomial have ? I am not sure about this one...I wanna say 1 because u can simplify it if it has more then 1...but I am not 100% sure on this one
3x^2 + 6xy -10x^5 + y^6 - 10x^3y^5
when u have a polynomial with more then 1 variable, such as this one, the degree is not the highest exponent, it is the highest term.....-10x^3y^5...u add the exponents....so this term has a degree of 8, and it is the highest one in this problem....so this is an 8th degree polynomial with 5 terms
        
             
        
        
        
12 pieces 
3 pieces = 1 yard
Multiply 4 by 3 because the log is 4 yards long 
That will give you 12 total pieces 
        
             
        
        
        
The answer or number that you are looking for is -6.4. You can get this by dividing 3 by 5 which is equal to 0.6. Next you would subtract 7 to reverse the act of having added it. This will give you -6.4 which is what you are looking for.