Buka kurung 2 akar 5 ditambah 3 tutup kurung buka kurung akar 6 dikurangi 3 akar 5 tutup kurung

(2√5 + 3)(√6 – 3√5)
= 2√5(√6 – 3√5) + 3(√6 – 3√5)
= 2√(5×6) – (2x3x√5²) + 3√6 – 3²√5
= 2√30 – 6×5 + 3√6 – 9√5
= 2√30 – 30 + 3√6 – 9√5
= 2√30 + 3√6 – 9√5 – 30
= √6(2√5 + 3) – 3(3√5 + 10)