Ответ:

  1. Вычисляем корни: \(\sqrt{2601}=51\), \(\sqrt{144}=12\).

    \(51-7\cdot12=51-84=-33\).

  2. \(\sqrt{900}=30\), \(\sqrt{64}=8\).

    \(0{,}1\cdot30-\frac14\cdot8=3-2=1\).

  3. \(\sqrt{2500}=50\), \(\sqrt{0{,}16}=0{,}4\), \(\sqrt{121}=11\).

    \(50\cdot0{,}4+11=20+11=31\).

  4. \(\sqrt{0{,}64}=0{,}8\), а \(\sqrt{42+22}=\sqrt{64}=8\).

    \(4\cdot0{,}8-8=3{,}2-8=-4{,}8\).

  5. \(\sqrt{784}=28\), \(\sqrt{256}=16\).

    \(28-8\cdot16=28-128=-100\).

Ответ: −33; 1; 31; −4,8; −100.