The number (√5+2)/(√5-2) is: (a) a rational number (b) an irrational number (c) an integer (d) a natural numbe

Question

The number (√5+2)/(√5-2)
is:
(a) a rational number
(b) an irrational number
(c) an integer
(d) a natural number

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Ngọc Diệp 3 years 2021-08-26T04:01:16+00:00 1 Answers 6 views 0

Answers ( )

  1. Eirian
    0
    2021-08-26T04:02:32+00:00
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    Answer:

    b:  irrational

    Step-by-step explanation:

      (√5+2)

    ————–  is given.

      (√5 – 2)

    If we multiply numerator and denominator by (√5+2), we succeed in removing the square root symbol from the denominator:

    (√5+2)(√5+2)

    ———————

    (√5+2)(√5- 2)

    and the denominator becomes 5 – 2, or 3.  The denominator is now rational, but the numerator still involves the square root symbol, so overall the given number is irrational.

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