Question

(√15+4)(√15-4)=_____​

Answer 1

Answer:

$\small\mathfrak\green{Verified Answer}$

Step-by-step explanation:

x+√15=4

x=4-√15

so putting x in x+1/x

4-√15+1/(4-√15)

above equation can also be written as

(4-√15)/1+1/(4-√15)

taking lcm of 1 & 4–√15

So lcm is 4-√15

((4-√15)²+1)/(4-√15)

(16+15–8√15+1)/(4-√15)

(32–8√15)/(4-√15)

Taking 8 common from numerator

8(4-√15)/(4-√15)

4-√15 is cancelled from numerator and denominator so

Ans= 8

Answer 2

Hey mate! This is your answer.

Answer:

-1

Step-by-step explanation:

The identity used in this question is:

(a + b) (a - b) = $a^{2} - b^{2}$

(√15+4)(√15-4)= $(\sqrt{15})^{2} - 4^{2}$

The square of 4 is 16.

When a number in root is squared, then the root symbol gets cancelled.

So, 15 - 16 = (-1)

(√15+4)(√15-4) = -1

Hope it helps!!

Please mark it as brainliest.