x^2-3x-10＞0x^2-3x+9/4-49/4＞0x^2-3x+9/4＞49/4（x-3/2）^2＞49/4x-3/2＞7/2或者x-3/2＜-7/2X>5 或X<-2
x^2-3x-10＞0(x+2)(x-5)＞0x＜-2，或x＞5
大于5或小于-2.
X>5 或X<-2
