Solve a surd ( 5-sqrt2)²?

2 Answers
Apr 12, 2018

27102

Explanation:

note that a×a=a

(52)2=(52)(52)

expand the factors using FOIL

(52)(52)

=255252+(2×2)

=25102+2=27102

Apr 13, 2018

27102

Explanation:

(52)2=(52)(52)

Multiply each term:

5×5=25

5×2=52

2×5=52

2×2=4=2

Collecting like terms:

25+2+(52)+(52)27102