Question

can anyone solve 4th and 8th question please guys I need help please solve step by step ​

Answer 1

Answer:

4) 98

Step-by-step explanation:

we know that x^2+ 1/x^2= (x-1/X)^2

given is X=5 - 2√6.

then 1/X is = 1/5-√6=

5+2√6/ (5-2√6) (5+2√6) = 5+2√6/ 5^2-(2√6)^2

= 5+2√6/ 25-24 = 5+2√6/1 = 5+2√6.

Then, x^2 +1/X = ( --2√6 (5+2√6))^2 + 2

therefore,(-4√6)^2 +2= 96+2= 98

so the answer is 98