Mohon dijawab soal nomor 1-3 ya! Terima kasih sebelumnya.

1. [tex](7a^{-4}b^6)^2[/tex]
[tex]=7^2(a^{-4})^2(b^6)^2[/tex]
[tex]=49a^{-4.2}b^{6.2}[/tex]
[tex]=49a^{-8}b^{12}[/tex]
[tex]=\frac{49b^{12}}{a^8}[/tex]
2. [tex]\sqrt{28}-\sqrt{175}-2\sqrt7[/tex]
[tex]=\sqrt{4.7}-\sqrt{25.7}-2\sqrt7[/tex]
[tex]=2\sqrt{7}-5\sqrt{7}-2\sqrt7[/tex]
[tex]=-5\sqrt{7}+2\sqrt{7}-2\sqrt7[/tex]
[tex]=-5\sqrt{7}[/tex]
3. [tex]\frac4{\sqrt5+3}[/tex]
[tex]=\frac4{\sqrt5+3}\times\frac{\sqrt5-3}{\sqrt5-3}[/tex]
[tex]=\frac{4(\sqrt5-3)}{(\sqrt5+3)(\sqrt5-3)}[/tex]
[tex]=\frac{4\sqrt5-4.3}{(\sqrt5)^2-3^2}[/tex]
[tex]=\frac{4\sqrt5-12}{5-9}[/tex]
[tex]=\frac{4\sqrt5-12}{-4}[/tex]
[tex]=\frac{4\sqrt5}{-4}-\frac{12}{-4}[/tex]
[tex]=-\sqrt5-(-3)[/tex]
[tex]=3-\sqrt5[/tex]
semoga membantu, mohon dikoreksi bila ada kesalahan