Question

I am a rational number. Multiply me by 4 to get my reciprocal. I am

Answer 1

$Let \: a \: rational \: number = \frac{a}{b}$

$Reciprocal \: of \: \frac{a}{b} = \frac{b}{a}$

/* According to the problem given */

$\frac{a}{b} \times 4 = \frac{b}{a}$

$\implies \frac{a}{b} \times \frac{a}{b} = \frac{1}{4}$

$\implies \Big( \frac{a}{b}\Big)^{2} = \Big(\frac{1}{2}\Big)^{2}$

$\implies \frac{a}{b} = \pm \sqrt{ \Big(\frac{1}{2}\Big)^{2}}$

$\implies \frac{a}{b} = \pm \frac{1}{2}$

Therefore.,

$\red{ Required \:rational \:number } \green { = \pm \frac{1}{2}}$

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Answer 2

Answer:

see. it's damn easy

Step-by-step explanation:

4×a/b=b/a

4a/b=b/a

cross multiply:

a²/b²=1/ 4

a/b=√1/4

a/b=1/2

as they said reciprocal so : 1/2 =2