Question

Calculati:
a)(√45-√5)²-(√11-√13)(√13+11)
b)(√3-√12)²-(√7+√11)(√11-√7)
c)$\frac{7}{ \sqrt{11-2} } - \frac{2}{ \sqrt{11-3} }$
d)$\frac{2}{ \sqrt{6+2} } + \frac{3}{ \sqrt{6+3} }$

Answer 1

b)(√3-√12)²-(√7+√11)(√11-√7)=(3--2√36+12)-(√77-7+11-√77)=(15-2·6)-(+4)=
3-4=-1
c) =  7/√9-2/√8=7/3-2/2√2=7/3-1/√2=(7√2-3)/3√2=
[3√2(7√2-3)]/9·2=[21·2-9√2)/18=(24-9√2)/18=3(8-3√2)/18=(8-3√2)/6
asa se face si celalalt