Answer:
Step-by-step explanation:
Let a , b , c & d be the no. of chairs in hall A , B , C & D respectively.
Given,
b = 4a
c = a + 15
d = a + 8 + 4a = 5a + 8
Now,
Total no. of chairs (T) = a + b + c + d
= a + 4a + a + 15 + 5a + 8
= 11a + 23
Now,
Average chairs in each hall (Avg) = T/4
= (11a + 23)/4
Answer:
B
Step-by-step explanation:

It looks like your first selection (a) is appropriate.
answer
D 2
factor
factor the equation
into (x + a) and (x + b) so that a + b = -2 and a * b = -8
the two numbers that meet these conditions are a = -4 and b = 2

find solutions
set both (x - 4) and (x + 2) equal to zero to find your solutions
x - 4 = 0
x = 4
x + 2 = 0
x = -2
add solutions
since the two solutions are x = 4 and x = -2, add them together to get your final answer
4 + (-2) = 2