16x^4-81y^4  difference of perfect squares...
(4x^2-9y^2)(4x^2+9y^2)  that's one of the equivalents...
(2x+3y)(2x-3y)(4x^2+9y^2)  that's another one of them...
        
             
        
        
        
The constant of proportionality k is 3.5
Step-by-step explanation:
Proportionality describes any relationship that is always in the same
ratio
If two quantities x and y are in proportionality, then
1. y ∝ x
2. y = k x , where k is the constant of proportionality
∵ x ⇒    6    ,    7      ,    8    ,    9
∵ y ⇒    21   ,   24.5 ,    28  ,    31.5  
∵ y ∝ x
∴ y = k x
- Use x = 6 and y = 21 to find the value of k
∵ x = 6 and y = 21
∴ 21 = k (6)
- Divide both sides by 6
∴ k = 3.5
- Use x = 7 and y = 24.5 to find the value of k
∵ x = 7 and y = 24.5
∴ 24.5 = k (7)
- Divide both sides by 7
∴ k = 3.5
- Use x = 8 and y = 28 to find the value of k
∵ x = 8 and y = 28
∴ 28 = k (8)
- Divide both sides by 8
∴ k = 3.5
- Use x = 9 and y = 31.5 to find the value of k
∵ x = 9 and y = 31.5
∴ 31.5 = k (9)
- Divide both sides by 9
∴ k = 3.5
The constant of proportionality k is 3.5
Learn more:
You can learn more about proportionality in brainly.com/question/10708697
#LearnwithBrainly
 
        
             
        
        
        
Answer: Each piece is 1 2/3 inch length.
Step-by-step explanation:
 Total length of cookie dough =10-inch
Since it is being into divided  into 6 equal-length pieces
We have that each piece will have=1 0-inch / 6 = 5/3 = 1 2/3 inch length.
 
        
             
        
        
        
This is fairly simple. Divide 2,871,000 by 10 and that's your answer!

Also, since you're dividing by a factor of 10 (or in this case, <em>10</em>) you can just take away as many places as are zeros in the number you're dividing from. This works for <em>10, 100, 1,000, 10,000, etc. </em>In this case, since there is only one zero in 10 you only take away one place marking, which gives you 287,100.
 
        
        
        
155 divided by 17 =
9.1176