Show 5+root 7 is irrational
Answers
Step-by-step explanation:
Let 5 +√7 be a rational number.
A rational number can be written in the form of p/q where p,q are integers.
5 +√7 = p/q
5 = p/q-√7
Squaring on both sides,
(5)² = (p/q-√7)²
25 = p²/q² + √7² - 2(p/q)(√7)
√7×2p/q = p²/q²+7-25
√7 = p²/q² - 18
√7 = (p²-18q²)/q² × q/2p
√7 = (p²-18q²)/2pq
p,q are integers then (p²-18q²)/2pq is a rational number.
Then, √7 is also a rational number.
But this contradicts the fact that √7 is an irrational number.
So,our supposition is false.
Therefore, 5+√7 is an irrational number.
Also refer :
https://brainly.in/question/1380388
https://brainly.in/question/2179266
HOPE IT HELPS..!
Explanation:
:we know that √7 is an irrational number.
:we know that √7 is an irrational number.The sum of rational number and an irrational number is always irrational number
5 is a rational number
√7 is an irrationa number