mathml

There are a lot if issues with the code you have, so I’ve just written something new… $result = [“<mo>+</mo><mi>x</mi><mo>=</mo><mfrac><mrow><mo>-</mo><mi>b</mi><mo>±</mo><msqrt><msup><mi>b</mi><mn>2</mn></msup><mo>-</mo><mn>4</mn><mi>a</mi><mi>c</mi></msqrt></mrow><mrow><mn>2</mn><mi>a</mi></mrow></mfrac>”, “<mo>+</mo><mi>x</mi><mo>+</mo><mn>2</mn><mo>=</mo><mn>3</mn>”, “<mfrac><mrow><mn>2</mn><mi>x</mi><mo>+</mo><mn>2</mn></mrow><mn>3</mn></mfrac><mo>-</mo><mn>3</mn><mo>=</mo><mn>2</mn>”, “<mo>-</mo><mn>3</mn><mo>+</mo><mn>2</mn><mo>=</mo><mi>x</mi>” ]; $arr_result=[]; for ($i=0; $i < count($result) ; $i++) { if (substr($result[$i],0,4)!=”<mo>”) { $arr_result[]= “<mo>+</mo>”.$result[$i]; } else { $arr_result[]= $result[$i]; } } print_r($arr_result); This just goes through each line at a time, … Read more