решить неравенство x^+4x-12>5x
x^2+4х-5x-12>0
x2-x-12=0
D=b2-4ac=1+48=49
x1,x2=-b+(-)7\2
x1=4
x2=-3
x^+4x-12-5x
x^-x-12=0
D=1^-4*1*(-12)=49
x1/2=1+/-7/2=-3;4