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

Speed of an object at one instant of time is the object's_____ speed.​
What is the congruence theorem used to prove that the two triangles are congruent?
what is -2(3x^2-7x+4)+(x+1)(x-7)
Hi! I just need the equation for how to solve it, then plug the numbers into it, and then the answer. Please do #4, and if u want to do #5 for extra points (I’l
Who did Alexander III make the target of persecution?
if it costs 3.99 for 24 ounces how much woud it cost for 1
Solve the system of equations by substitution.y=3x-10,3x+2y=16
Which best explains surface tension A.capillary action B.cohesion C.adhesion D.sublimation
How do you expand polynomials?
4 ft ≈_m help me pleaseeeeeeeeee