Question

Show that 5 +2 √7 is an irrational number, where √7is given to be an irrational

number​

Answer 1

Answer:

5+2√7 is irrational

Step-by-step explanation:

let 5+2√7 be rational

but it is given that √7 is irrational:-

so,

our assumption was wrong

5+2√7 is irrational

hence proved

Answer 2

Answer:

5 +2 √7 is an irrational number

Step-by-step explanation:

5+2√7=a/b ( a and b are co prime , b=/= 0)

2√7=a-5/b

√7=1/2(a-5b/b)

if 1/2(a-5b/b) is rational no and then root 7 is also rational number

but given that root 7 is a irrational number and 1/2(a-5b/b)is also irrational number.

our assumption was wrong.

therefore 5 +2 √7 is an irrational number.