If 18, a, b, -3 are in A.P., then a + b is equal to​

Question

If 18, a, b, -3 are in A.P., then a + b is equal to​

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Julia 1 month 2021-08-19T05:14:48+00:00 1 Answer 0 views 0

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  1. Emma
    0
    2021-08-19T05:15:51+00:00

    Step-by-step explanation:

    first term (a) = 18 ——-(1)

    formula of A.P = a+(n-1)*d

    fourth term = a+(4-1)d = a+3d —(2)

    solve (1) and (2)

    a = 18

    a+3d = -3

    3d = 21

    d= 21/3

    d= 7

    To find a+b

    a= a+d = 18-7 = 11

    b= a+2d = 18-2(7) = 18-14 = 4

    so, a+b= 11+4 = 15

    hope this helps you, please thank and follow

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