The binomial theorem states that for any positive integer n, the expansion of (a + b)^n can be found using the formula: (a + b)^n = nC0 * a^n * b^0 + nC1 * a^(n-1) * b^1 + nC2 * a^(n-2) * b^2 + ... + nCr * a^(n-r) * b^r + ... + nCn * a^0 * b^n, where nC0, nC1, ..., nCr represents the binomial coefficients.