已知方程x^2-mx-m=3=0的两个根为x1,x2,若两根都大于-5,求实数m的取值范围.

x1+x2=mx1x2=-m+3x1>-5,x2>-5x1+5>0,x2+5>0都大于0则相加和相乘都大于0所以(x1+5)+(x2+5)=x1+x2+10=m+10>0m>-10(x1+5)(x2+5)>0x1x2+5(x1+x2)+25>0-m+3+5m+25>0m>-7判别式大于等于0m²+4m-12>=0(m-2)(m+6)>=0m=2...