8)
a= 4√10-2√8-(6+4√10)=4√10-4√2-6-4√10=-4√2-6
a nu este nr intreg
b=2(4+√21)-6√7+2√7×(3-√3)=
=8+2√21-6√7+6√7-2√21=
=8
c=4√3(√8-√3)-2√2×(3√3-√2)=
=4√3(2√2-√3)-2√2×(3√3-√2)=
=8√6-4×3-6√6+4=2√6-12+4=2√6-8
c nu este nr intreg
9)
a) 2√132:√11+14√30:2√10+9√21:√7-6√3=
= 2√12+7√3+9√3-6√3=
= 4√3+7√3+9√3-6√3=
=14√3
b) (3√2-√5)×√3+√2×(√3-√20)+√5×(√3+√8)=
= 3√6-√15+√2×(√3-2√5)+√5×(√3+2√2)=
= 3√6-√15+√6-2√10+√15+2√10=
= 4√6
c)√48×(2√75-√27+2√27)-√48×√12=
=4√3×(10√3-3√3+6√3)-4√3×2√3=
=4√3×13√3-24=
=156-24=132
d)√243×√147-2√3×7√3+3√8(5√72+6√128)=
=9√3×7√3-14×3+6√2(30√2+48√2)=
=63×3-14×3+6√2×78√2=
=189-42+936=
=1083
