<h2><u>Part A:</u></h2>
Let's denote no of seats in first row with r1 , second row with r2.....and so on.
r1=5
Since next row will have 10 additional row each time when we move to next row,
So,
r2=5+10=15
r3=15+10=25
<u>Using the terms r1,r2 and r3 , we can find explicit formula</u>
r1=5=5+0=5+0×10=5+(1-1)×10
r2=15=5+10=5+(2-1)×10
r3=25=5+20=5+(3-1)×10
<u>So for nth row,</u>
rn=5+(n-1)×10
Since 5=r1 and 10=common difference (d)
rn=r1+(n-1)d
Since 'a' is a convention term for 1st term,
<h3>
<u>⇒</u><u>rn=a+(n-1)d</u></h3>
which is an explicit formula to find no of seats in any given row.
<h2><u>Part B:</u></h2>
Using above explicit formula, we can calculate no of seats in 7th row,
r7=5+(7-1)×10
r7=5+(7-1)×10 =5+6×10
r7=5+(7-1)×10 =5+6×10 =65
which is the no of seats in 7th row.
The mean score is 3.08.
There is 1 quiz with score 1, so 1 point; 3 quizzes with score 2 for 3*2 = 6 points; 4 quizzes with score 3 for 4*3 = 12 points; 4 quizzes with score 4 for 4*4 = 16 points; and 1 quiz with score 5 for 5 points.
This is a total of 1+6+12+16+5 = 40 points.
This is out of 1+3+4+4+1 = 13 quizzes.
40/13 = 3.08
Answer:
Step-by-step explanation:
x + 2 + 57 = 90
x + 59 = 90
x = 31°
x + 2 = 33°
K = -18 to check, -4 + k/3 = -10 is the equation. -18/3 = -6, and -4 + -6 = -10. Mark as branliest if you can. :)

The 2nd choice is appropriate.