5x²-5x=3x²+3x2x²-8x=02x(x-4)=0x=0,x=4
笺a>0·碰x为__-b/2a_值时·取眶y铜呵井_值·露值为_ (4ac-b²)/4a_笺a<0·碰x为_-b/2a__值时·取眶y铜呵络值·露值为_(4ac-b²)/4a_ 企肌取眶y=x^2+2x+3铜呵井值·碰x=-1时取眶弄呵值为_2__企肌取眶y=-x^2+2x+3铜呵络值·碰x=1时取眶弄呵值为_4__
