Question

Efectuati: /-linie de fractie
a.) (2-√2)-(√2+3)+2√2+4
b.) (3/√3+2/√2)*(√3-√2)
c.) (7/3-√2+5/√7+√2)*(3-√7)

Answer 1

a.) (2-√2)-(√2+3)+2√2+4=
2-√2-√2-3+2√2+4=3

b.) (3/√3+2/√2)*(√3-√2)=
(3√3/3+2√2/2)(√3-√2)=
(√3+√2)(√3-√2)=
3-2=1

c.) (7/3-√2+5/√7+√2)*(3-√7)=
(7/3-√2+5√7/7+√2)(3-√7)=
[(49+15√7)/21](3-√7)=
(147-49√7+45√7-105)/21=
(42-4√7)/21=
42/21-4√7/21=
2-4√7/21