HOC24
Lớp học
Môn học
Chủ đề / Chương
Bài học
Câu D
1) A=x2−6x+11=(x2−6x+9)+2A=x2−6x+11=(x2−6x+9)+2
=(x−3)2+2≥2=(x−3)2+2≥2
minA=2⇔x=3minA=2⇔x=3
2) B=2x2+10x−1=2(x2+5x+254)−272B=2x2+10x−1=2(x2+5x+254)−272
=2(x+52)2−272≥−272=2(x+52)2−272≥−272
minB=−272⇔x=−52minB=−272⇔x=−52
3) C=5x−x2=−(x2−5x+254)+254C=5x−x2=−(x2−5x+254)+254
=−(x−52)2+254≤254=−(x−52)2+254≤254
maxC=254⇔x=52maxC=254⇔x=52
4) D=−8x2+6≤6D=−8x2+6≤6
maxD=6⇔x=0
2b)=(x−2y)(x+2y)−2(x−2y)=(x−2y)(x+2y−2)
mik giúp r nhé
3)a,⇒x2−x−2=x2⇒x=−2b,⇒x(x−3)−4(x−3)=0⇒(x−4)(x−3)=0⇒[x=3x=4c,⇒x(2x−1)2=0⇒⎡⎣x=0x=12d,⇒x3−x2+4x2−4x+7x−7=0⇒(x−1)(x2+4x+7)=0⇒[x=1(x+2)2+3=0(vô.lí)⇒x=1
bạn ghi ra rõ đc k mik nhìn hơi khó
27wrote
28 got
29 is going to get
30 came
31 will call - arrive
32 saw - has lost - grown
33 is knocking - will open
34 think - is knocking
bạn cần câu mấy
dài quá mình giúp ko nổi sorry nhá!
=25y2+6xy+10x2/10x2y3
1Firstly
2 Secondly
3 Thirdly
4 Moreove
5 For these reasons