Question

x²减4x减5分之x的绝对值减5等于0,求x的值

Answer 1

(|x|-5)/(x²-4x-5)=0

则分子为0,分母不等于0

|x|-5=0

|x|=5

x=±5

x=5,x²-4x-5=0,舍去

所以x=-5