makingachange2 makingachange2
  • 22-01-2022
  • Mathematics
contestada

Determine the sum of the first 20 terms of an arithmetic sequence in which first
terms is 31 and the twentieth term is 109

Respuesta :

sqdancefan
sqdancefan sqdancefan
  • 22-01-2022

Answer:

  1400

Step-by-step explanation:

The average term is the average of the first and last terms.

  average term = (31 +109)/2 = 70

The sum of the 20 term is 20 times the value of the average term:

  S20 = 20(70) = 1400

Answer Link

Otras preguntas

To do a research, a researcher needs to be clear about what he/she is doing, why he/she is doing it and the associated implications of what he/she is about to d
How do I do this ?????
4 1A contar! Escribe. Write the number of sounds each one of the following words has chico silla juguete queso hijo 000 cheque español hermano casa anillo amor
Rewrite the expression 18+30=
Standard Precautions mean blood, body fluids, non-intact mucous membranes as if the means treating all intact skin, and as if they were
Which of these situations produces the largest profits for oligopolists? a. The firms reach a Nash equilibrium. b. The firms reach the competitive outcome. c. T
The current in a hair dryer measures 15 amps the resistance of the hair dryer is 8 ohms
Help on number 11 please?​
A website where a writer or group of writers shares their own experiences and opinions is a
PEOPLESS PLEASE HELP WHAT IS 4/5 × 2/3?​