Let's solve in <math><mi>ℝ</mi></math>: <math><mi>x</mi><mo> + </mo><mn>5</mn><mo> = </mo><mn>9</mn></math>
 <math><mi>x</mi><mo> = </mo><mn>9</mn><mo> -</mo><mn>5</mn></math>

▷<b>Answer: &nbsp; <math><mi>x</mi><mo> = </mo><mn>4</mn></math></b><span style='font-size:smaller'> &nbsp; &nbsp; (computation took 2 steps and 2 ms)</span>