tolong aku lagi yaa kak........... tanggal 01/29/2018 mau dikumpul :(

(√2 - 2√3)² = (√2 - 2√3)(√2 - 2√3)
                  = 2 - 2√6 - 2√6 + 12
                  = 14 - 4√6


(√3 - 3√5)(√3 + 3√5)
= 3 + 3√15 - 3√15 - 45
= -42


(7√3 + 8√2)(6√3 + 5√2)
= 126 + 35√6 + 48√6 + 80
= 206 + 83√6

jangan lupa teliti ulang ya dek, g'luck :)

No. 8
[tex] {( \sqrt{2} - 2 \sqrt{3}) }^{2} \\ = ( \sqrt{2} {)}^{2} + (2 \times \sqrt{2} \times - 2 \sqrt{3} ) + ( -2 \sqrt{ 3 } {)}^{2} \\ = 2 - 4 \sqrt{6} + 12 \\ = 14 - 4 \sqrt{6} [/tex]
No. 9

[tex]( \sqrt{3} {)}^{2} + ( \sqrt{3} \times 3 \sqrt{5} ) + ( - 3 \sqrt{5 } \times \sqrt{3} ) + ( - 3 \sqrt{5} \times 3 \sqrt{5} ) \\ = 3 + 3 \sqrt{15} - 3 \sqrt{15 } - 45 \\ = - 42[/tex]