Question

Can any one say me how this 2(47+21√5)came

Answer 1

hello mate.....
In pic 2 is taken as common that why 94 becomes 47 and 42√5become 21√5....

Answer 2

hey friend!
ur solution!
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$\frac{49 + 45 + 42 \times \sqrt{5} }{4} \\ = > now \: we \: add \: only \: digit \: number \\ we \: cannot \: plus \: the \: irrational \\ number \: which \: is \: \sqrt{5} \\ \\ so \\ \\ = > \frac{94 + 42 \sqrt{5} }{4} \\ \\ take \: common \\ \\ = > \frac{2(47 + 21 \sqrt{5} )}{4} \\ \\now \: divide \: 2 \: and \: 4 \\ \\ = > \frac{47 + 21 \sqrt{5} }{2} \\ \\ hope \: u \: understand \\ \\ thanks$