By the binomial theorem,

where

Then the coefficients of the 
 terms in the expansion are, in order from 
 to 
,





 
        
             
        
        
        
Answer:
20 pens
Step-by-step explanation:
if there is 1 red pen for every 4 blue pens
then
4 red pens would have 16 blue pens with it. makes a total of 20 pens, with 12 more blue pens than red pens
 
        
             
        
        
        
Answer:
length of chord is 6cm
Step-by-step explanation:
Here, we are to calculate the length of the chord.
It should be understood that the chord has a length of 0.8cm from the center of the circle of radius 3cm, thereby forming two right-angled triangles with the radius 3cm being the hypotenuse of each and 0.8cm being the height of each.
Now, the chord is divided into 2 by this height dropping from the center of the circle. To calculate the first half, we use Pythagoras’ theorem with 3cm being hypotenuse and 0.8cm being the other side. 
mathematically;
3^2 = 0.8^2 + l^2
9 = 0.64 + l^2
l^2 = 9-0.64
l^2 = 8.36
l = √(8.36)
l = 2.89 approximately 
The length of the chord would be 2l = 2 * 2.89 = 5.78 cm which is 6cm to the nearest length 
 
        
             
        
        
        
Answer:
1)164%
Step-by-step explanation:
plus them you'll get the answer
 
        
             
        
        
        
Answer: (-5,0) 
Step-by-step explanation:
-4x + 5y = 20   the x intercept is when y is zero so input zero into the equation and solve for x. 
-4x + 5(0) = 20 
-4x = 20 
x = -5