5x{(24-19)x[(25+23)divided by 12-(9-7)]}

Rewriting that,

5*{(24-19)[(25+23)/12 -(9-7)]}

= 5{(5)[(48)/12 -(2)]}

= 5{5[4 -2]}

= 5{5[2]}

= 5{10}

= 50

You need explanations per step?

Follow each step above and ask me what you don't understand.

I am sure your teacher or your books taught you about doing first the insides of the parentheses, per groupings, etc....