Write 6(x – 5)4 + 4(x – 5)2 + 6 = 0 in the form of a quadratic by using substitution. a. 6u2 + 4u + 6 = 0, where u = x – 5 b. 6u2 + 4u + 6 = 0, where u = (x – 5)2 c. 6u4 + 4u + 6 = 0, where u = x – 5 d.6u4 + 4u + 6 = 0, where u = (x – 5)2the answer is  b. 6u2 + 4u + 6 = 0, where u = (x – 5)2