\(\rm\frac{\sqrt{x+20}+\sqrt{x-1}}{\sqrt{x+20}-\sqrt{x-1}}=\frac{7}{3}\)అయితే, \(\rm \sqrt{(x + 20)(x-1)}\) విలువ ఏమిటి??

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Option 3 : 10
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ఇచ్చిన:

\(\rm\frac{√{x+20}+√{x-1}}{√{x+20}-√{x-1}}=\frac{7}{3}\)

సత్వరమార్గ ట్రిక్At x = 5,

\(\rm\frac{√{5+20}+√{5-1}}{√{5+20}-√{5-1}}=\frac{5+2}{5-2}=\frac{7}{3}\)

అందువల్ల, అవసరమైన విలువ

\(⇒ \rm √{(x + 20)(x-1)} = √{(25\times4)}\)

⇒ √100 =  10

ప్రత్యామ్నాయ పద్ధతి

ఉపయోగించిన భావన:

కాంపోనెండో మరియు డివిడెండో (రివర్స్):

(a + b ) : (a – b) = (c + d) : (c – d) అయితే ,  అప్పుడు  a : b = c : d 

లెక్కింపు:

\(\rm\frac{√{x+20}+√{x-1}}{√{x+20}-√{x-1}}=\frac{7}{3}\)

⇒ \(\rm\frac{√{x+20}}{√{x-1}}=\frac{7+3}{7-3}= \frac{10}{4}\)

⇒ \(\rm\frac{√{x+20}}{√{x-1}}=\frac{5}{2}\)

రెండు వైపులా స్క్వేర్ చేయడం, 

⇒ \(\rm\frac{{x+20}}{{x-1}}=\frac{25}{4}\)

⇒ 4x + 80 = 25x – 25

⇒ (25x – 4x) = (80 + 25)

⇒ 21x = 105

⇒ x = 5

 \(\rm √{(x + 20)(x-1)}\)యొక్క విలువ

⇒ \(\rm √{(5 + 20)(5-1)}\)

⇒ \(\rm √{(25\times 4)}\) = √100

\(\rm √{(x + 20)(x-1)}\) = 10

∴ అవసరమైన విలువ 10.

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