Let's factorize in <math><mi>ℝ</mi></math>: <math><mn>9</mn><msup><mrow><mi>x</mi></mrow><mrow><mn>2</mn></mrow></msup><mo> -</mo><mn>4</mn></math>
This expression can be factorized into: <math><mo>(</mo><mn>3</mn><mi>x</mi><mo> -</mo><mn>2</mn><mo>)</mo><mo>·</mo><mo>(</mo><mn>3</mn><mi>x</mi><mo> + </mo><mn>2</mn><mo>)</mo></math>

▷<b>Answer: &nbsp; <math><mo>(</mo><mn>3</mn><mi>x</mi><mo> + </mo><mn>2</mn><mo>)</mo><mo>·</mo><mo>(</mo><mn>3</mn><mi>x</mi><mo> -</mo><mn>2</mn><mo>)</mo></math></b><span style='font-size:smaller'> &nbsp; &nbsp; (computation required 2 steps and 5 ms)</span>