Question

Prove that 3-2√5 is irrational no.​

Answer 1

Let 3-2√5 be a rational number and say it "x".

x=3-2√5

squaring

${x }^{2} = 29 - 20 \sqrt{5 }$

now, x2-29/-20=√5

sincs lhs is rational but lhs is irrational,

then this whole term is irrational!

thanks!!