Question

solve the 13th sum plz fast​

Answer 1

Answer:

Step-by-step explanation:

given

a^2-5a-1=0

a^2-5a=1

a^2-1=5a

divide a

i)a-1/a=5

a^2+1/a^2-2=25

a^2+1/a^2=27

II)a+1/a=?

(a+1/a)^2=a^2+1/a^2+2

=27+2=29

a+1/a=sqrt(29)

III) (a^2-1/a^2)

=(a+1/a)(a-1/a)

=27sqrt(29)

Answer 2

Answer:

Hey mate, Good morning ♡

#Here's ur answer...♤♡◇♧

Step-by-step explanation:

$1)a - \frac{1}{a} = \frac{a {}^{2} - 1 }{a} \\ given \: a {}^{2} - 1 = 5a \\ \frac{a {}^{2} - 1}{a} = 5(ans)$

$a {}^{2} - 5a - 1 + 2 = 2 \\ a {}^{2} - 5a + 1 = 2 \\ a + \frac{1}{a} = \frac{a {}^{2} + 1 }{a} \\ a {}^{2} + 1 = 5a + 2 \\ \frac{a {}^{2} + 1}{a} = 5 + \frac{2}{a} (ans)$

$then \: multiply \: both \: to \: get \: 3$

Hope this helps u...

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