Important Formulas in Algebra ; If n is a natural number an – bn = (a – b)(an-1 + an-2b+…+ bn-2a + bn-1) ; If n is even (n = 2k), an + bn = (a + b)(an-1 – an-2b + ... https://www.dailycompoundinterestcalculator.com/2023/08/common-algebra-formulas.html