1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
ch4aika [34]
3 years ago
7

Find the sum of the following without actually adding: 1+3+5+7+9+11+13+15

Mathematics
2 answers:
-Dominant- [34]3 years ago
7 0

Answer:

Step-by-step explanation:

The following numbers are successive odd numbers.

The sum of successive odd numbers (starting from 1) is always the square of number of terms you are adding.

Hear there are 8 terms. Square of 8 is 64.

Hence the sum of this numbers is<u> 64</u>.

I am Lyosha [343]3 years ago
6 0

use this formula Sn=n/2[2a+(n-1)d]

here,d=a2-a1 and n= no. Of terms

Step-by-step explanation:

S8=8/2[2(1)+(8-1)2]

S8=64

You might be interested in
All of them no words<br> extra points coming
KATRIN_1 [288]
6x + 9 < 3             3x - 8 > 13
6x < 3 - 9              3x > 13 + 8
6x < - 6                 3x > 21
x < -6/6                   x> 21/3
x < -1                      x > 7
solution is : x < -1 or x > 7
====================
4x + 5 > 25
4x > 25 - 5
4x > 20
x > 20/4
x > 5
===================
5 - 2x > = 27
-2x > = 27 - 5
-2x > = 22
x < = -22/2
x < = -11
==================
-2 < = x - 7 < = 11
-2 + 7 < = x - 7 + 7 < = 11 + 7
5 < = x < = 18

6 0
4 years ago
Read 2 more answers
24 POINTS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Nostrana [21]
Red:green

5:3
5+3=8
8 units
4qt=8 units
divide by 8
0.5qt=1unit
5 unit=red
5*0.5=2.5qt, red=2.5qt
3unit=lime
0.5*3=1.5qt
1.5qt, 2/3 of that is yellow, 1/3 is blue, 1.5 times 2/3=1, 1.5 times 1/3=0.5
result:
2.5qt red
1qt yellow
0.5qt blue

6 0
4 years ago
I know it’s a lot to ask but please show your work so I know how to do it. Thank you!
jonny [76]

Answer:

The answer to your question is below

Step-by-step explanation:

Use trigonometric functions to find x

13.  cos 40 = 5/x

     x = 5 / cos 40

     x = 5 / 0.766

     x = 6.5

14. tan 25 = x/9

     x = 9tan 25

     x = 9(0.466)

     x = 4.2

15.- cos 65 = x/12

      x = 12 cos 65

      x = 12 (0.423)

      x = 5.1

16.- sin 32 = 15/x

      x = 15 / sin 32

      x = 15 / 0.53

      x = 28.3

17.- tan 55 = 20 / x

      x = 20 / tan 55

      x = 20 / 1.42

      x = 14

18.- sin31 = x / 18

     x = 18 sin 31

     x = 18 (0.52)

     x = 9.3

8 0
3 years ago
If cos theta is -5/13 and sin θ &lt; 0, what is tan θ ?
tensa zangetsu [6.8K]
Take the right angled triangle  with sides 13, 12 and 5. sine theta will be 12/13

When sin theta < 0 and cos theta < 0  we are in the  third  quadrant  so sin theta will be -12/13

tan theta = sin theta / cos theta  = -5/13 /  -12/13   = -5*13 / -12*13 =  5/12
 
7 0
3 years ago
The radius is longer than the diameter.<br><br> A) never true<br><br> B) always true
sweet [91]

Answer:

a) never true

Step-by-step explanation:

a radius is always half of a diameter

6 0
3 years ago
Other questions:
  • 3016÷13 help.me please​
    9·2 answers
  • Ok I have a question it says, " Ella can read 2 pages in 3 minutes. How long will it take her to read 45 pages?". So I just don'
    14·1 answer
  • When evaluating proportions, we write the ratios in fractional form and then we ________________.
    15·2 answers
  • Eli left his house one afternoon to study at the library
    10·1 answer
  • Dado os intervalos A=(x e r/-4&lt; x &lt;2 )e b =(x e r/-2&lt; x &lt;4 )
    11·1 answer
  • A rectangle has a height of 3 and a width of 3x^2 +4x
    6·1 answer
  • 1/4 divided by 5/6 = 1/a× b/c
    6·1 answer
  • CAN SOMEONE PLEASE HELP! I WILL MARK BRIANLIEST
    6·2 answers
  • A school was painted by 8 men in 6 days. How long would it have taken 24 men.
    6·2 answers
  • In a factory, 50 out of 1,000 pens are found to be defective.
    9·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!