\(\vphantom{\frac{0}{0}}{\largeа)}\ 80+y^2=81\)
\(\phantom{\largeа)}\ y^2=81-80\)
\(\phantom{\largeа)}\ y^2=1\)
\(\phantom{\largeа)\ }\begin{array}[t]{ll}y_1={-}\sqrt1&\largeи&y_2=\sqrt1\\[-1ex]\\y_1={-}1&\largeи&y_2=1\end{array}\)
\(\vphantom{\frac{0}{0}}{\largeб)}\ 19+c^2=10\)
\(\phantom{\largeб)}\ c^2=10-19\)
\(\phantom{\largeб)}\ c^2={-}9\)
\(\phantom{\largeб)\ }\)нет корней
\(\vphantom{\frac{0}{0}}{\largeв)}\ 20-b^2={-}5\)
\(\phantom{\largeв)}\ b^2=20+5\)
\(\phantom{\largeв)}\ b^2=25\)
\(\phantom{\largeв)\ }\begin{array}[t]{ll}b_1={-}\sqrt{25}&\largeи&b_2=\sqrt{25}\\[-1ex]\\b_1={-}5&\largeи&b_2=5\end{array}\)
\(\vphantom{\frac{0}{0}}{\largeг)}\ 3x^2=1{,}47\)
\(\phantom{\largeг)}\ x^2=1{,}47:3\)
\(\phantom{\largeг)}\ x^2=0{,}49\)
\(\phantom{\largeг)\ }\begin{array}[t]{ll}x_1={-}\sqrt{0{,}49}&\largeи&x_2=\sqrt{0{,}49}\\[-1ex]\\x_1={-}0{,}7&\largeи&x_2=0{,}7\end{array}\)
\({\largeд)}\ \frac{1}{4}a^2=10\)
\(\phantom{\largeд)}\ a^2=10:\frac{1}{4}\)
\(\phantom{\largeд)}\ a^2=10\cdot4\)
\(\phantom{\largeд)}\ a^2=40\)
\(\phantom{\largeд)\ }\begin{array}[t]{ll}a_1={-}\sqrt{40}&\largeи&a_2=\sqrt{40}\end{array}\)
\(\vphantom{\frac{0}{0}}{\largeе)}\ {-}5y^2=1{,}8\)
\(\phantom{\largeе)}\ y^2=1{,}8:({-}5)\)
\(\phantom{\largeе)}\ y^2={-}0{,}36\)
\(\phantom{\largeе)\ }\)нет корней
