Fill in the blank. What is the sum of the roots of the polynomial shown below? f(x) = 3×3 + 12×2 + 3x – 18

Question

Fill in the blank. What is the sum of the roots of the polynomial shown below? f(x) = 3×3 + 12×2 + 3x – 18

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Thành Đạt 4 years 2021-09-02T14:34:18+00:00 1 Answers 18 views 0

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  1. linhdan
    0
    2021-09-02T14:35:56+00:00
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    Answer:

    -4

    Step-by-step explanation:

    Ok first we can factor out 3x and get

    f(x)=3(x^3+4x^2+x+6)

    then factor it

    f(x)=3(x^2(x-1)+5x(x-1)+6(x-1))\\f(x) = 3(x-1)(x^2+5x+6)\\f(x) = 3(x-1)(x+3)(x+2)\\x = 1, -3, -2

    add em together, we get -4

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Giải phương trình 1 ẩn: x + 2 - 2(x + 1) = -x . Hỏi x = ? ( )