Question

x^2-x=90

求解·· 最好详细点··

Answer 1

由x^2-x=90
得x^2-x-90=0
因式分解档州租中得行型蔽：(x-10)(x+9)=0
得x-10=0或x+9=0
得解x=10或x=-9

Answer 2

x^2-x-90=0
(x-10)(x+9)=0
x=10,x=-9

Answer 3

x^2-x=90
x^2-2*(1/2)x+(1/2)^2=90+(1/2)^2
(x-1/2)^2=361/4
x-1/2=根亩拦号361/2
x=（根号迅芹胡361+1）首羡/2

Answer 4

X^2-X=X*(X-1)=90=9*10=(-10)*(-9)
所以X=10或X=-9

Answer 5

x平吵镇早方旅仔-x=90
x平方-x-90=0
用十字相乘法..求得.十字相乘法好容易学升雀会.上百度找一下就有了
(x-10)(x+9)解得x=10,x=-9..负号舍去..所以x=10

Answer 6

10