Question

Prove that root 5 is irrational. Hence prove that -3+2root5 is irrational

Answer 1

Answer:

Step-by-step explanation:

let √5 be a rational number

√5=a/b(a,b are co-prime integer and b≠0)

a=b√5

a²=5b²

------>5 is the factor of a²

------->5 is the factor of a

let. a=5c (c is some integer)

a²=25c²

5b²=25c²

b²=5c²

-------->5 is the factor of b²

--------->5 is the factor of b

therefore 5 is a common factor of a, b

but this contradiction the fact that a, b are co-primes

therefore √5 is irrational

!!!!!!please mark it as brainliest!!!!!!