Answer:
this should be right if not comment and I'll relook it.
FOIL Method.
You will get the same answer x^2+ 7x- 18
 
        
                    
             
        
        
        
Let us assume that the number of beige tiles bought by Susan = B
Number of red tiles bought by Susan = R
Number of navy-blue tiles bought by Susan =N
Number of tiles bought altogether = 435
Now from the given question we know:
Number of red tiles bought is 25 more than the number of beige tiles.
So
 R = 25 + B
Number of navy blue tiles bought is 3 times that of the number of beige tile bought
So 
N = 3B
We already know that the total number of tiles bought is 435
Hence
B + R + N = 435
B + (25 + B) + 3B = 435
5B + 25 = 435
5B = 435 -25
5B = 410
B = 82
R = 25 + B
   = 25 + 82
   = 107
N = 3B
   = 3 * 82
   = 246
So the number of Beige tiles  bought by Susan = 82
The number of red tiles bought by Susan = 107
The number of navy-blue tiles bought by Susan = 246 
        
             
        
        
        
Answer:
Step-by-step explanation:
Given that there are 3 sets such that  there are 100 elements in A1, 1000 in A2, and 10,000 in A3
a) If A1 ⊆ A2 and A2 ⊆ A3
then union will contain the same number of elements as that of A3
i.e. 
b) If the sets are pairwise disjoint.
union will contain the sum of elements of each set

c) If there are two elements common to each pair of sets and one element in all three sets
We subtract common elements pairwise and add common element in 3
i.e. 