Which expression is equivalent to this polynomial? 16×2 + 4 A. (4x + 2i)(4x − 2i) B. (4x + 2)(4x − 2)

Question

Which expression is equivalent to this polynomial?
16×2 + 4
A.
(4x + 2i)(4x − 2i)
B.
(4x + 2)(4x − 2)
C.
(4x + 2)2
D.
(4x − 2i)2

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Farah 3 years 2021-08-06T21:56:43+00:00 1 Answers 49 views 0

Answers ( )

  1. thuthuy
    0
    2021-08-06T21:58:18+00:00
    Reply

    Answer:

    A.

    Step-by-step explanation:

    C and D do not create any x² terms when doing the multiplications. so, they are out.

    B stands for (a+b)×(a-b) = a² – b².

    so, that would give us a “-4” at the end and is not fitting to the “+4” term at the end of the original expression.

    that leaves us with A.

    let’s verify :

    (4x+2i)(4x-2i)

    it follows the same rule as B :

    (a+b)(a-b) = a² – b²

    a = 4x

    b = 2i

    you remember, i = sqrt(-1).

    so, we get

    (4x)² – (2i)² = 16x² – 4×(sqrt(-1))² = 16x² – 4×(-1) = 16x²+4

    bingo !

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