Two consecutive coefficients in the expansion of (1+ x)^n are 91 and 364. Prove that if they are the coefficients of the terms in x^r and x^(r+1), respectively, then n = 5r+4

Use the formulas a = x 2 – y 2, b = 2xy, c = x 2 + y 2 to answer this question. one leg of a right triangle has length 11 and all sides are whole numbers. find the lengths of the other two sides. the other leg = a0 and the hypotenuse = a1