Solve the following radical equations. Verify your solutions.

  1. \(\sqrt {y - 1} = 7\)

    \(\begin{align}
     y - 1 &\ge 0 \\
     y &\ge 1, y \in \rm R \\
     \end{align}\)


    \(\begin{align}
     \sqrt {y - 1} &= 7 \\
     \left( {\sqrt {y - 1} } \right)^2 &= 7^2  \\
     y - 1 &= 49 \\
     y &= 50 \\
     \end{align}\)


    Verify:

    Left Side
    Right Side
    \(\begin{array}{r}
     \sqrt {y - 1}  \\
     \sqrt {50 - 1}  \\
     \sqrt {49}  \\
     7 \\
     \end{array}\)

    \(7\)
    LS = RS

  2. \(\sqrt[5]{{4x}} = 2\)

    Because the index is \(5\) (odd), there are no restrictions on the variable, \(x \in \rm R\).

    \(\begin{align}
     \sqrt[5]{{4x}} &= 2 \\
     \left( {\sqrt[5]{{4x}}} \right)^5 &= 2^5  \\
     4x &= 32 \\
     x &= 8 \\
     \end{align}\)


    Verify:

    Left Side
    Right Side
    \(\begin{array}{r}
     \sqrt[5]{{4x}} \\
     \sqrt[5]{{4\left( 8 \right)}} \\
     \sqrt[5]{{32}} \\
     2 \\
     \end{array}\)

    \(2\)
    LS = RS\(\hspace{30pt}\)