Maths please help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!?

Question

Maths please help!!!!!!!!!!!!!!!!!!!!!!!!!!…
Evaluate ,(2+√5)^2 writing your answer in the form a+b√5

please answer and tell me how to do it

Brandon · Answer

(2+√5)^2
=2^2+(√5)^2+2*2*√5
=4+5+4√5
=9+4√5

Nehal J · Answer

(2+√5)^2
=2^2+(√5)^2+2*2*√5
=4+5+4√5
=9+4√5

Using the identity : (a+b)^2=a^2+b^2+2*a*b

pink sapphires · Answer

(2+√5)^2 = (2+√5) (2+√5)
              = (2)(2) + (2)(√5) + (2)(√5) + (√5)(√5)
              = 4 + 2√5 + 2√5 + 5
              = 9 + 4√5
Edit: Nehal's way is more straightforward, and actually better.

Sonali Naik · Answer

(2+sqrt5)^2=4+4sqrt5+5
[bcoz (a+b)^2=a^2+2ab+b^2]
=9+4sqrt5
so a=9 & b=4

Maths please help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!?

4 Antworten