Perform Distribution on a input string containing an X (Basic Math)

I am getting an input string that could look like one of the following:

• 2(6x-1)
• 3x + 4(8-x)

I want to do this respectively

• 12x-2
• 3x+32-4x

How can I do this in Perl without using pre-made modules? I can't use eval() because of the X