How do you FOIL (5 - 2√2)^2(522)2?

1 Answer
May 26, 2015

Problem: FOIL (5-2sqrt2)^2(522)2 .
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(5-2sqrt 2)(5-2sqrt 2)(522)(522)

Firsts: 5*5=2555=25

Outers: 5*-2sqrt 2=-10sqrt 2522=102

Inners: -2sqrt2*5=-10sqrt2225=102

Lasts: 2sqrt 2*2sqrt 2=4sqrt 2sqrt 2=4*sqrt(2xx2)=4sqrt4=4*2=82222=422=42×2=44=42=8

Combine the terms.

25-10sqrt2-10sqrt2+825102102+8 =

25-20sqrt 2+825202+8 =

33-20sqrt 233202