The first term of an arithmetic sequence is -30 and the common difference is 8. Find the 20:n term.

n = 15

Explanation:

This is an

Arithmetic sequence

The sum of the first n terms of this sequence is given by.

S

n

=

n

2

[

2

a

+

(

n

−

1

)

d

]

where a is the first term and d , the common difference.

here a = -16 , d = 8 and require to solve for n.

hence :

n

2

[

(

2

×

−

16

)

+

8

(

n

−

1

)

]

=

600

n

2

[

−

32

+

8

n

−

8

]

=

600

⇒

n

2

(

8

n

−

40

)

=

600

distributing gives :

4

n

2

−

20

n

−

600

=

0

Equated to zero since this is a quadratic equation.

⇒

4

(

n

2

−

5

n

−

150

)

=

0

⇒

4

(

n

+

10

)

(

n

−

15

)

=

0

⇒

n

=

−

10

or

n

=

15

but n > 0 hence n = 15

Step-by-step explanation:

answer: a. 13/44

step-by-step explanation: judging by the information given to us, we are looking for experimental probability. we can see that 13 males have chosen chocolate ice cream. there are 44 ice creams in total (remember that the total is always the denominator). so our answer is 13/44.

answer: the distance

step-by-step explanation:

to calculate the distance d of a line segment with endpoints (x1, y1) and (x2, y2) use the formula d (x2 x1)2 (y2 y1)2. to calculate the midpoint of a line segment with endpoints (x1, y1) and (x2, y2) use the formula