Упростите: а) \(\sqrt{15\cdot121}\); б) \(\sqrt{16\cdot900}\); в) \(\sqrt{1,44\cdot36}\); г) \(\sqrt{0,81\cdot0,49}\).

1. \(\sqrt{15\cdot121}=\sqrt{15}\cdot\sqrt{121}=11\sqrt{15}\).
2. \(\sqrt{16\cdot900}=\sqrt{16}\cdot\sqrt{900}=4\cdot30=120\).
3. \(\sqrt{1,44\cdot36}=\sqrt{1,44}\cdot\sqrt{36}=1,2\cdot6=7,2\).
4. \(\sqrt{0,81\cdot0,49}=\sqrt{0,81}\cdot\sqrt{0,49}=0,9\cdot0,7=0,63\).

Ответ: а) \(11\sqrt{15}\); б) \(120\); в) \(7,2\); г) \(0,63\).