... 311 15>−x HD: <=>−<><=>−<−>−2 15 32 311 15 311 15xxxx b/ Tìm x . Biết 25452≥+−x <=>−≤≥< = >−≤−≥−8 13 215 2 215 2xxxx ... <=>−==< = >=+=−< = >=+=− 1, 238 ,1 02,42038 ,1 0/2, 412 /0/38 ,1/ yxyxyx c/ 0)3) (1( 32=−++−xxxx HD: c/3 31 300)3) (1( 0)3(=< = >−==< = >=−+=−xhoacxhoacxxxxxd/ ... chứa dấuGTTĐ" {2 /13 32 /1 03 012 03 12 )(4 /1 2 /1 03 012 03 12 <<−< = >−><< = >>+<−<...