Question

Aratati ca numerele a,b si c sunt intregi:
a=4 √10 -2√8 -(6+4 √10)=
b=2(4+√21 )-6 √7+2 √7· (3- √3) =
c=4√3(√8-√3)-2√2·(3√3-√2)

Answer 1

a=4√10-2*2√2-6-4√10
a=-4√2-6∉Z

b=8+2√21-6√7+6√7-6√21
b=8-4√21∉Z

c=4√3(2√2-√3)-6√6+4
c=8√6-12-6√6+4
c=2√6-8∉Z
a,b,c nu sunt nr. intregi