C d tolong dijawab ya,pakai jalan. Tolong bantuannya

c.
[tex] = 7 \sqrt{5} - ( \sqrt{20} + \sqrt{5} ) \\ = 7 \sqrt{5} - ( \sqrt{4 \times 5} + \sqrt{5} \\ = 7 \sqrt{5} - (2 \sqrt{5} + \sqrt{5} ) \\ = 7 \sqrt{5} - 3 \sqrt{5} \\ = 4 \sqrt{5} [/tex]
d.
[tex] = \sqrt{48} + \sqrt{32} - \sqrt{8} \\ = \sqrt{16 \times 3} + \sqrt{16 \times 2} - \sqrt{4 \times 2} \\ = 4 \sqrt{3} + 4 \sqrt{2} - 2 \sqrt{2} \\ = 4 \sqrt{3} + 2 \sqrt{2} [/tex]