Question

1Calculati::
a)(√4+√5)–¹+(√5+√3)–¹=
b)(√4+√7)–¹+(√7+√16)–¹=

Answer 1

acele semne ce inseamna mai exact?

Answer 2

a)=1/(√4+√5)+1/(√5+√3)=rationalizam adica inmultim si la numarator si la numitor la prima fractie cu √4-√5 iar la a doua fractie cu √5-√3

=[(√4-√5)/(√4+√5)(√4-√5)]+[(√5-√3)/(√5+√3)(√5-√3)]
=[(√4-√5)/(4-5)]+[(√5-√3)/(5-3)]
=[(√4-√5)/-1]+[(√5-√3)/2]
=-(√4-√5)/1+(√5-√3)/2   aducem la acelasi numitor
=[-2(√4-√5)+√5-√3]/2
=(-2√4-2√5+√5-√3)/2
=-(2√4+√5+√3)/2

b)= 1/(√4+√7)+1/(√7+√16)
=1/(√4+√7)+1/(√7+4)
=[(√4-√7)/(4-7)]+[(√7-4)/(7-16)]
=[(√4-√7)/-3]+[(√7-4)/-9]
=-(√4-√7)/3-(√7-4)/9
=-3(√4-√7)/9-(√7-4)/9
=(-3√4+3√7-√7+4)/9
=(-3√4+2√7+4)/9