tolong dibantu ya pakai jalan makasih:)

≡ penyelesaian :

nomor 8.) [ opsi. C ]

[tex] = \sqrt{80} + 2 \sqrt{45} - \sqrt{245} \\ \\ = \sqrt{( {4}^{2} \times 5)} + 2 \sqrt{( {3}^{2} \times 5)} - \sqrt{( {7}^{2} \times 5) } \\ \\ = 4 \sqrt{5} + (2 \times 3) \sqrt{5} - 7 \sqrt{5}\\ \\ = 4 \sqrt{5} + 6 \sqrt{5} - 7 \sqrt{5} \\ \\ = 3 \sqrt{5} [/tex]

nomor 9.) [ opsi. D ]

[tex] = ( {4}^{ - 3} \times {2}^{4} ) {}^{ - 2} \\ \\ = (( {2}^{2} ) {}^{ - 3} \times {2}^{4} ) {}^{ - 2} \\ \\ = ({2}^{ - 6} \times {2}^{4} ) {}^{ - 2} \\ \\ = ({2}^{ - 2} ) {}^{ - 2} \\ \\ = {2}^{4} \\ \\ = 16 [/tex]

nomor 10.) [ opsi. A ]

[tex] = \sqrt{6} \times \sqrt[3]{8} \times \sqrt[4]{36} \\ \\ = \sqrt{6} \times 2\sqrt[4]{36} \\ \\ = \sqrt[4]{6^2} \times 2\sqrt[4]{36} \\ \\ = \sqrt[4]{36 \times 36} \times 2 \\ \\ = \sqrt[4]{1296} \times 2 \\ \\ = 6 \times 2 \\ \\ = 12 [/tex]