prove that 2+5√7 is irrational no.
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Hey... I think this can be ur answer!!
Let us assume that 2+5root7 is irrational
Now,
2+5root7 = a/b (a and b are Co prime)
5root7 = a/b-2 = a-2b/b
Root7 = a-2b/5b
BUT we know that root7 is irrational
Hence, 2+5root7 is irrational
So, our assumption was wrong
Hence proved!!
Let us assume that 2+5root7 is irrational
Now,
2+5root7 = a/b (a and b are Co prime)
5root7 = a/b-2 = a-2b/b
Root7 = a-2b/5b
BUT we know that root7 is irrational
Hence, 2+5root7 is irrational
So, our assumption was wrong
Hence proved!!
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