Please can someone explain how to rearrange a regression equation?

I can't find any guides online and I got banned from discord for asking as the question was deemed too difficult for graduates.

my equation is:
output_filesize = (initial_bitrate * initial_bitrateCoef) + (orig_bitrate * orig_bitrateCoef) + (avc_Codec * avc_CodecCoef) + (mpjgCodec * mpjg_CodecCoef) + (height * heightCoef) +(width * widthCoef)+ (duration * durationCoef) + (frames * framesCoef) + (original_filesize * original_filesizeCoef) + interceptCoef


and I want to rearrange the terms so that it gives me the "initial bitrate" variable for a known filesize.

so
output_filesize = ...

I know I need to do something with the initial_bitrate and its coefficient but there are no guides online. if anyone could point me to one too or some examples thanks.

This is a serious question and despite having advanced STEM education I keep returning negative values. I think I am rearranging the equation wrong. Thanks.