calculus and algebra

I am looking for help with advanced problem-solving in calculus differential and algebra, with a focus on solving equations. I need an experienced and knowledgeable freelancer who can help me tackle complex equations and understand the theory behind them. The task will include work on derivatives and integrals, as well as linear equations. I need the freelancer to have a mastery of mathematics and be able to provide clear explanations. The freelancer should refrain from providing solutions without any explanations.