arithmetic

The 8th term of an A P is 5times the third term while the 7th term is 9 greater than the 4th term.what are the first five term

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  1. term(3) = a+2d
    term(8) = a+7d
    a+7d = 5(a+2d)
    a+7d = 5a + 10d
    -4a = 3d
    a = -3d/4

    in the same way
    a+6d = (a+3d) + 9
    3d = 9
    d = 3
    then a = -9/4

    first 5 terms are: -9/4, 3/4, 15/4, 27/4, 39/4
    or -2.25, .75 , 3.75, 6.75, 9.75

    check:
    term(8) = 18.75
    term(3) = 3.75
    what is 5(3.75) ?

    term(7) = 15.75
    term(4) = 6.75 , do they differ by 9 ? ,YES

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  2. No

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  3. -2.5,.75,3.75,6.75,9.75

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