Question

高中数学题：如图

已重发

Answer 1

由已知得当c>0时，原不等式可化为1/c<a，即c>1/a
当c<0时，原不等式可化为-b<1/c，即c<-1/b
综上可得原不等式等价于c>1/a或c<-1/b

Answer 2

c cannot be 0

if c>0 1/c>-b(c>0) we get 1>-bc(b>0) we get c>1/-b
1/c<a (c>0) we get 1<ac (a>0) we get c>1/a
since 1/-b smaller than 1/a we get c>1/a

if c<0 similarly we can get c<-1/b

therefore -b<1/c<a is same as c<-1/b when c<0 or c>1/a when c>0

Answer 3

Sorry!! 看不清图，你放大再发吧