esl13
contestada

HELP me plz
I'm in year 9 in England and I got this question. I have no idea what to do

HELP me plzIm in year 9 in England and I got this question I have no idea what to do class=

Respuesta :

sum of two consecutive terms is 145
let the numbers be the nth and (n+1)th term

nth term = 5n+10
(n+1)th term = 5(n+1)+10 = 5n+5+10 = 5n+15

5n+10 + 5n+15 = 145
⇒ 10n + 25 = 145
⇒ 10n = 145-25 = 120
⇒ n = 120/10 = 12

terms are:
5n+10 = 5 x 12 + 10 = 70
5n + 15 = 5 x 12 + 15 = 75