Home › Forums › Math › Which equation shows the quadratic formula used correctly to solve 7×2 = 9 + x for x? › Reply To: Which equation shows the quadratic formula used correctly to solve 7×2 = 9 + x for x? July 19, 2021 at 3:23 pm #10034 hemanthkParticipantUp0Down::For this case we have the following quadratic equation: 7x²=9+x Rewriting the equation we have: 7x² – x – 9 = 0 Here, a = 7, b = -1, c = -9 Now, b² – 4ac (-1)² – 4.7.(-9) 1+252 253 Therefore, x = – b±(b²-4ac)^(1/2) / 2ax = – (-1)±(253)^(1/2) / 2.7x = 1±(253)^(1/2) / 14
