3x^2=21x

To solve the equation \(3x^2 = 21x\), we can start by rearranging it into standard quadratic form:

1. Subtract \(21x\) from both sides to set the equation to zero: \[ 3x^2 - 21x = 0 \]

2. Next, we can factor out the common term \(3x\): \[ 3x(x - 7) = 0 \]

3. Now, we can set each factor equal to zero: \[ 3x = 0 \quad \text{or} \quad x - 7 = 0 \]

4. Solving these equations gives us:

   • From \(3x = 0\): \[ x = 0 \]
   • From \(x - 7 = 0\): \[ x = 7 \]

Thus, the solutions to the equation \(3x^2 = 21x\) are: \[ x = 0 \quad \text{and} \quad x = 7 \]