how many terms added 24+20+16+-.. to make the sum of 72 ​

Question

how many terms added 24+20+16+…… to make the sum of 72

in progress 0
Caroline 4 days 2021-10-11T04:25:07+00:00 2 Answers 0 views 0

Answers ( )

    0
    2021-10-11T04:26:34+00:00

    Answer:

    Step-by-step explanation:

    24+20+16+x=72

    60 +x = 72

    X= 72 -60

    X= 12

    0
    2021-10-11T04:27:02+00:00

    Answer:

    Step-by-step explanation:

    Given A.P is 24,20,16,…

    so, the first term, a=24

    the common difference, d=20−24

    =−4.

    The sum of first n terms of A.P is given by

    2

    n

    [2a+(n−1)d]=

    2

    n

    [48−(n−1)4]

    Given, the sum is 72.

    so,  

    2

    n

    [48−(n−1)4]=72

    ⇒24n−n(n−1)2=72

    ⇒2n

    2

    −26n+72=0⇒n

    2

    −13n+36=0

    ⇒n=4 or 9.

    ∴ 4 terms and 9 terms add upto 72.

    I HOPE IT HELPS YOU

Leave an answer

Browse

14:4+1-6*5-7*14:3+5 = ? ( )