Ответ:

  1. Айырма квадраттары формуласын қолданамыз: \(165^2-124^2=(165-124)(165+124)=41\cdot289\).
    \[\sqrt{\frac{165^2-124^2}{164}}=\sqrt{\frac{41\cdot289}{4\cdot41}}=\sqrt{\frac{289}{4}}=\frac{17}{2}=8\frac12.\]
  2. \(176^2-112^2=(176-112)(176+112)=64\cdot288\).
    \[\sqrt{\frac{98}{176^2-112^2}}=\sqrt{\frac{98}{64\cdot288}}=\sqrt{\frac{49}{9216}}=\frac7{96}.\]
  3. \(149^2-76^2=73\cdot225\), ал \(457^2-384^2=73\cdot841\).
    \[\sqrt{\frac{73\cdot225}{73\cdot841}}=\frac{15}{29}.\]
  4. \(145,5^2-96,5^2=49\cdot242\), ал \(193,5^2-31,5^2=162\cdot225\).
    \[\sqrt{\frac{49\cdot242}{162\cdot225}}=\sqrt{\frac{49\cdot121}{81\cdot225}}=\frac{77}{135}.\]

Жауап: 1) 8½; 2) 7/96; 3) 15/29; 4) 77/135.