Prove that root 7/5 +4 is an irrational

1.	Prove that root 7/5 +4 is an irrational
Answer» Let a=√7/4+5 is a rational number.a×4+5=√7Since a×4+5 is a rational number.But we know that,√7 is anirrational number.This contradicts due to our wrong supposition.Therefore,a=√7/4+5 is an irrational number.Hence prooved.

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