Ask question

Ask question

All categories

2 years ago

11

What is the sum of the first 11 terms of the arithmetic series in which a1= -12 and d=5?

1 answer:

SVEN [57.7K]2 years ago

3 0

Hello :
the terme general is : an = a1 +(n-1)d
a11 = a1+(11-1)×5
a11 = -12+50
a11 = 38
<span>the sum of the first 11 terms is : S11 = (11/2)(a1+a11)
</span>S11 = (11/2)(-12+38)
S11 = 143

You might be interested in

Can someone please help me with number 37?

Romashka [77]

Answer:

<h2>x = 10</h2>

Step-by-step explanation:

$4-(3x-5)=6-(2x+7)\\\\/-(a+b)=-1(a+b)=(-1)(a)+(-1)(b)-\text{distributive property}/\\\\4-3x-(-5)=6-2x-7\\\\4-3x+5=6-2x-7\qquad\text{combine like terms}\\\\-3x+(4+5)=-2x+(6-7)\\\\-3x+9=-2x-1\qquad\text{subtract 9 from both sides}\\\\-3x+9-9=-2x-1-9\\\\-3x=-2x-10\qquad\text{sdd}\ 2x\ \text{to both sides}\\\\-3x+2x=-2x+2x-10\\\\-x=-10\qquad\text{change the signs}\\\\\boxed{x=10}$

3 0

2 years ago

Read 2 more answers

Xavier collected 12 shells at the beach. Nora collected 5 fewer than Xavier. How many shells did Nora collect?

Ulleksa [173]

Answer:

7, Nora collected 7 shells.

Step-by-step explanation:

Xavier collected 12 shells whilist she collected 5 fewer then Xavier.

12 - 5 = 7

Therefore, Nora collected 7 shells at the beach.

8 0

2 years ago

Write a mathematical expression for the word expression. Seven times a number plus one

abruzzese [7]

Answer:

7x +1

Step-by-step explanation:

7 0

2 years ago

Read 2 more answers

dente has been putting one penny in his bank everyday. now je has 161 pennies. for how many weeks has dente been adding pennies

SIZIF [17.4K]

23

1 day is equal to 0.14285714 weeks, so multiply that by the number of days.

7 0

2 years ago

Read 2 more answers

1) Andrew owns 220 shares of a common stock in a tech company. The tech company recently paid a cash dividend of $2.25 per share

Iteru [2.4K]

Answer:

9.0

Step-by-step explanation:

Took the test

5 0

3 years ago