✔ 最佳答案
sum of roots = a + b = -b / a = -(-2) / 1 = 2
product of roots = ab = c / a = -6 / 1 = -6
Sum of roots of the required equation
= (a﹣2b) + (b﹣2a)
= -a﹣b
= -(a + b)
= -2
product of roots of the required equation
= (a﹣2b)(b﹣2a)
= ab﹣2a2﹣2b2 + 4ab
= 5ab﹣2(a2 + b2)
= 5ab﹣2(a2 + b2 + 2ab﹣2ab)
= 5ab﹣2[(a + b)2﹣2ab]
= 5ab﹣2(a + b)2 + 4ab
= 9ab﹣2(a + b)2
= 9(-6)﹣2(2)2
= -62
The required quadratic equation is
x2﹣(Sum of roots)x + product of roots = 0
x2 + 2x﹣62 = 0