a) The expression is y = 140 - 15 x
b ) There are 5 participants in the 9th round
Step-by-step explanation:
Step 1 :
From the graph we can see that,
Number of people in the singing competition = 140
Number of people in the first round = 125
Number of people in the second round = 110
Number of people in the third round = 95
Number of people in the fourth round = 80
Number of people in the fifth round = 65
Step 2 :
From the given data, We can get that the difference between the number of people participating in each round is 15 less than the previous round .
The first round has 15 people less than the total number 140
Let x represent the number of the round and y represent the number of people participating in each round .
Then the expression to represent this would be
y = 140 - 15 x
Step 3 :
To find the number of participants in the 9th round given the same pattern continues.
For the 9th round x = 9, as x represents the number of the round
Substituting this in the equation obtained in step 2, we get
y = 140 -15 (9) = 140 - 135 = 5
There are 5 participants in the 9th round
Step 4 :
Answer :
a) The expression is y = 140 - 15 x
b ) There are 5 participants in the 9th round
