Question

if x= (2+√5), find the value of xsquare​

Answer 1

Answer:

$x = (2 + \sqrt{5} ) \\ x {}^{2} \: \: \: = (2 + \sqrt{5} ) {}^{2} \\ x {}^{2} = \: 2 {}^{2} + ( \sqrt{5} ) {}^{2} + 2 \times 2 \times \sqrt{5} \\ x {}^{2} \: = 4 + 5 + 4 \sqrt{5} \\ x {}^{2} \: = 9 + 4 \sqrt{5}$

Answer 2

Answer: 9+4√5

Step-by-step explanation:

given, x= (2+√5)

therefore $x^{2} = (2+\sqrt{5} )^{2}$

(2^2+√5^2+2x2x√5)

= 4+5+4√5

= 9+4√5