cho cac so a, b, c thoa man: a(a-b)+b(b-c)+c(c-a)=0
tim gia tri nho nhat cua bieu thuc: A=a^3+b^3+c^3-3abc+3ab-3c+5
giai chi tiet giup to may bai nay nha
1. Cho tam giac ABC co trung tuyen AM . Goi I la trung diem cua AM. Tia BI cat AC tai D, qua M ke duong song song voi BD cat CD tai E. Biet BD=18cm , khih do ID = ? cm
2. gia tri lon nhat cua bieu thuc Q= 5-x2+2x2-4y2-4y
3 . gia tri cua x thoa man (12x-5)(4x-1)+(3x-7)(1-16x)=81 , x=?
4. x+y=3 , gia tri cua bieu thuc Q = x2+2xy+y2-4x-4y+1=?
5 . a+b+c=0 va abc=-2 thi a3+b3+c3= ?
6. rut gon bieu thuc(a2+b2)2-4a2b2voi a2-b2=5 ta duoc ket qua ?
cho x+y =1 . tinh gia tri cua bieu thuc A=x^3+y^3+3xy
chox-y=1. tinh gia tri cua bieu thuc B=x^3-y^3-3xy
cho x+y=1 . tinh gia tri cua bieu thuc C=x^3+y^3+3xy(x^2+y^2)+6x^2*y^2(x+y)
Cho 2 bieu thuc :
A=\(\dfrac{x-3}{x+2}va\) B= \(\dfrac{3}{x+3}+\dfrac{2}{x-3}-\dfrac{3x-9}{x^2-9}\left(x-2,x\ne3x\ne-3\right)\)
a, Tinh gia tri bieu thuc A khi x=5
b, Chung minh : B=\(\dfrac{2}{x-3}\)
c, Biet C = A.B, Tim x de c = \(\dfrac{-1}{3}\)
1) Phan tich da thuc sau thanh nhan tu: x2-x-2008.2009
2) Chung minh rang voi moi x,y,z ta luon co: x2+4y2+z2>=2x+12y+4z
3) Cho a-b=4. Tinh gia tri cua bieu thuc: a3-12ab-b3
cac ban lam duoc cau nao thi giup mik nha. mik dang can gap lam
1.gia tri x<0 thoa man (2x-3)2=(x+5)2
2.tap hop cac gia tri cua x thoa man x4-2x3+10x2-20x=0 la S(....)
3.phan tich da thuc xy-12+3x-4 ta duoc (x+a)(y+b) khi do a+b=?
Tim gia tri nho nhat cua cac bieu thuc sau
a) A=|5x+2|+2015
b) B=2016-|4-3x|
c) C=|x-4|+|x-3|
giup minh giai cac gia tri nay voi...dung minh se tich
HỨA SẼ TÍCH...
cau 1 cho x y la 2 so thoa man x2-y2 =2
vay gia tri cua bieu thuc A=2(x6-y6)-6(x4+y4)=.................
cau 2 ch da thuc A(X)=2X2 +ax+b
biet da thuc A(X) chia het cho da thuc B(x)=x-3 va C(x)=2x+1
vay 3a-2b=...................
Cho x+y=2, tinh gia tri cua bieu thuc:
M=3(x^2+y^2)-(x^3+y^3)+1
Bai 2:Cho a+b=5,tinh gia tri bieu thuc:
M=3a^2-2a+3b^2-2b+6ab+100