This interactive site is excellent in giving practice solving linear equations with one variable.
http://www.hellam.net/algebra/linear2.html
This interactive site gives practice solving quadratic equations. It uses the quadratic formula, and if you input values for a, b, and c for which the expression under the radical (b^2 – 4ac) is less than 0, the quadratic formula will return a complex number (which is beyond the scope of this course). For our use, make sure b^2 – 4ac is not less than zero, and you will obtain the desired result.
http://www.math.com/students/calculators/source/quadratic.htm
Fermat’s last theorem:
This is site from the PBS program, “The Proof”:
http://www.pbs.org/wgbh/nova/proof/
Fermat’s last theorem;
https://mathshistory.st-andrews.ac.uk/HistTopics/Fermat’s_last_theorem/