kandialliyah4460 kandialliyah4460
  • 24-04-2018
  • Mathematics
contestada

The 7th term of an arithmetic sequence is 1, and the 20th term is -25. find the 25th term.

Respuesta :

mkryukova19 mkryukova19
  • 24-04-2018
a(7)=1
a(20)=25
a(25)=?

a(n)=a(1)+d(n-1)

a(7)=a(1) +6d=1         -11/13+6*24/13= 
a(20)=a(1)+19d=-25

a(1) +6d=1
a(1)+19d=-25 (subtract first equation from the second)
---------------------
      19d-6d =-26
       13d =-26
d=-2

a(1)=1-6d=1-6*(-2)=13

a(25)= a(1)+d(25-1)= 13+(-2) *24= 13-48=-35
Answer Link

Otras preguntas

Identify the approximate color you would expect if you were to test each household item using a cabbage pH indicator.
SOMEONE PLSS HELP ITS URGENT!!!
Help me please thank you!!
Bella used 1/5 of a sheet of paper to make 4 price tags. What fraction of a whole sheet of paper is each price tag?​
Una bolsa contiene 4 canicas azules, 4 canicas rojas y 4 canicas verdes. Sacas aleatoriamente una canica y luego otra (sin reemplazo). ¿Cuál es la probabilidad
At the hot dog stand, it costs 18.39 for five hotdogs and six bags of chips. If it costs 4.63 for one hot dog and two bags of chips, how much is a hotdog?
What are the benefits of this individualized response? *​
Can someone please help
FIND THE VOLUME OF THE PRISM
Sue and Javier are working on a statistics project to estimate the proportion of students at their school who have a pet dog. Sue selects a random sample of 81