Answer:
An echo is formed as a result of reflection of the original sound which returns to the listener. You might have experienced Echo in an EMPTY ROOM but no echo is produced after the room is occupied. To avoid echo from being produced the echo has to be absorbed. Echo in a cinema theatre is absorbed by the WALLS of the theatre.
They are not plain. The walls are corrugated or shaped to form tiny holes or empty spaces to ABSORB the ECHO. Modern Theatre's have ABSORBENT materials sticked to the walls of the theatre.
Answer:
3c-9d+7c+5d becomes this when it is simplified 10c - 4d
Step-by-step explanation:
A+(-1.3)=-4.5
Add 1.3 to both sides of the equation
a=-3.2
Answer:
Asanji drove for 
hours before Huong caught up
Step-by-step explanation:
Let the time for which Asanji drove alone is "X" hours
Asanji and Huong met after three hours of driving of Huong.
Total time for which Asanji drove 
hours
Thus, distance travelled by Asanji in 
hours is equal to distance travelled by Huong in 
hours
On solving the above equation, we get -
Asanji drove for 
hours before Huong caught up
We have a parabola.
As it is concave down, we have one maximum and no minimum.
We can identify the maximum at point (-2, 4).
Answer: (-2,4)
