Work shown above! Answer would be A!
 
        
        
        
Answer:
R = rows
C = columns
 
The chairs will be arranged in a way such that R * C  70
 70
We know that R  20
 20
70 / 20 = 3.5; however, you can't have half of a chair. 
So find all the factors of 70 which don't exceed 20.
1, 70
2, 35
<h2>
5, 14</h2><h2>
7, 10</h2><h2>
</h2><h2>There are four ways that Brooke can set up the chairs:</h2><h2>5 rows of 14</h2><h2>7 rows of 10</h2><h2>10 rows of 7</h2><h2>14 rows of 5</h2>
 
        
             
        
        
        
Hello : 
<span> sin 2x = sin x and 0 ≤ x ≤ 2π.
all solutions : 
2x= x +2k</span>π    or x= π -x +2kπ ..... k in : Z
x = 2kπ  or : x = π/2 + kπ 
but : 
 <span>0 ≤ x ≤ 2π
</span><span>all values of x such that sin 2x = sin x and 0 ≤ x ≤ 2π are : 
</span>k = 0 : x=0    , x= π/2
k=1 : x=2 π    , x=3π/2