Request a call back

Join NOW to get access to exclusive study material for best results

ICSE Class 10 Answered

The 5th and 9th terms of an arithmetic progression are 4 and -12 respectively. Find (a) the first term (b) common difference (c) sum of 16 terms of the AP
Asked by varma.renu9481 | 13 Mar, 2023, 11:46: AM
answered-by-expert Expert Answer
Given: 5th term a5 = 4 and 9th term a9 = -12
straight a plus 4 straight d equals 4 space space space space space space space space... space left parenthesis straight i right parenthesis
straight a plus 8 straight d equals negative 12 space space... space left parenthesis ii right parenthesis
Subtracting space left parenthesis straight i right parenthesis space from space left parenthesis ii right parenthesis comma space we space get
4 straight d space equals space minus 16
straight i. straight e. space straight d space equals space minus 4
Therefore comma space straight a equals 20
First space term space equals space 20 space and space common space difference equals negative 4
Sum space of space 16 space terms equals 16 over 2 open square brackets 2 straight a plus open parentheses 16 minus 1 close parentheses straight d close square brackets equals 8 open square brackets 40 minus 60 close square brackets equals 8 left parenthesis negative 20 right parenthesis equals negative 160
Answered by Renu Varma | 13 Mar, 2023, 12:05: PM

Concept Videos

ICSE 10 - Maths
Asked by astonfern123 | 14 Jul, 2024, 20:01: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 10 - Maths
Asked by musarathh19 | 27 May, 2024, 19:45: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 10 - Maths
Asked by srilakshmivytla28 | 10 Sep, 2023, 09:19: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 10 - Maths
Asked by rashikulkarni28 | 14 Aug, 2022, 16:32: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 10 - Maths
Asked by rashikulkarni28 | 14 Aug, 2022, 16:30: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 10 - Maths
Asked by arpitadas4117 | 17 Jan, 2022, 14:13: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 10 - Maths
Asked by savithakotari962 | 08 Feb, 2021, 20:40: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
Are You a Teacher or a Parent Seeking Customised Tests? Click here
×