Let x be the units digit. Then the tens digit is (x+4), and the number is 10*(x+4) + x. We are given that 10*(x+4) + x = x*(x+4) + 52. It is your quadratic equation to find x. x^2 - 7x + 12 = 0. (x-4)*(x-3) = 0. The equation has two roots. Both satisfy the problem's condition. So, there are two solutions. At x= 3 the number is 73. At x= 4 the number is 84. Answer. There are two solutions: 73 and 84.