a) (2√12 - √27 + √3) × 3√3=
= (4√3 - 3√3 + √3) × 3√3=
= 2√3 + 3√3=
= 2×3×3=
= 18.
b) 2√2( √6-√15) -5√2√80=
= 2√2(√6-√15)-5√2 × 4√5=
= 2√2(√6-√15)- 20√2√5=
= 2√2(√6-√15- 10√5)=
