To determine if (1, 6) is a solution, substitute x = 1, y = 6 into the left side of both equations and if the value obtained equals the right side then it is a solution.
( y - 4 ) ( y² + 4 y + 16 ) = = y³ + 4 y² + 16 y - 4 y² - 16 y - 64 = y³ - 64 If the result is the polynomial of the form: y³ + 4 y² + a y - 4 y² - a y - 64 a = 16
