3x-5=19 xy²=648

To solve the equations you provided:

1. For the equation \(3x - 5 = 19\):

   Step 1: Add 5 to both sides. \[ 3x - 5 + 5 = 19 + 5 \] \[ 3x = 24 \]

   Step 2: Divide both sides by 3. \[ x = \frac{24}{3} = 8 \]

   So, \(x = 8\).

2. For the equation \(xy^2 = 648\):

   We can express \(y^2\) in terms of \(x\) or vice versa or find numerical solutions for specific values of \(x\) or \(y\). If we use \(x = 8\) (from the first equation):

   Step 1: Substitute \(x\) into the equation. \[ 8y^2 = 648 \]

   Step 2: Divide both sides by 8. \[ y^2 = \frac{648}{8} = 81 \]

   Step 3: Take the square root of both sides. \[ y = \sqrt{81} = 9 \quad \text{or} \quad y = -9 \]

   Thus, if \(x = 8\), then \(y = 9\) or \(y = -9\).

Summary:

• \(x = 8\)
• \(y = 9\) or \(y = -9\) (assuming \(x = 8\)).