what’s the y intercept and slope of all of them? I give

9514 1404 393

Step-by-step explanation:

The slope is found using the slope formula. It works well to choose ordered pairs that only differ by 1 in their x-value.

  m = (y2 -y1)/(x2 -x1)

The y-intercept is the y-value when x=0. If it is not in the table, it can be found from one point and the slope.

  b = y1 -m·x1

__

1) slope = (9 -3)/(2 -1) = 6

  y-intercept = -9 -6(-1) = -3

__

2) slope = (21 -(-1))/(2 -0) = 22/2 = 11

  y-intercept = -1 . . . from table for x=0

__

3) slope = (-9-(-11))/(2-1) = 2

  y-intercept = -11 -(2)(1) = -13

__

4) slope = (-4 -(-5))/(2 -1) = 1

  y-intercept = -7 -1(-1) = -6

step-by-step explanation: so we look at the formula un = a + (n-1)d

un is the amount of seats

n is the nth term aka row number

a is the original sequence/row number

d is the difference between each term

so in this a=22 d=6 and n can remain as n because we are simply formjng a rule

lets put these in the equation

un=22+(n-1)(6)

this is your answer to part a

however

lets double check that this is correct, we'll try putting it into the second term

un=a+(n-1)d

u2=22+(2-1)(6)

u2=22+6

u2=28

as the question said the second row has 28 seats so now we know the formula we made is correct.

as for part b

un=a+(n-1)

its asking us to find a row with 100 seats.

remember un was the amount of seata so all we do is substitute this in.

un=100 a=22 d=6

un=a+(n-1)d

100=22+(n-1)(6)

so now we simplify to find n which is the row number.

100-22=22+(n-1)(6)-22

78=(n-1)(6)

78/6=(n-1)(6)/6

13=n-1

13+1=n-1+1

14=n

so now we know that in the 14th row there is 100 seats.

hope this and that you understood! its my first time using the app or anyone out on here : p its also me to revise so a bunch! ask more questions if you dont understand ☺