Question

решите неравенство х*(4х-8)*(х+1)*(12-3х)<0

Answer 1

х(4х-8)*(х+1)*(12-3х)<0
(х+1)(12-3х)=х(4х-8)
12х-3х2 +12-3х=4х2-8х
-4х2+8х+12х-3х2 +12-3х=0
-7х2 +17х+12=0
-7х2 +17х+12=0*(-1)
7х2-17х-12=0
D=b2-4ac=(-17)2 -4*7*(-12)=625
X1=- 8/14
X2=3