a: ĐKXĐ: x<>2; x<>-2
b: \(A=\dfrac{3x\left(x-2\right)+2x+6}{2\left(x-2\right)\left(x+2\right)}=\dfrac{3x^2-6x+2x+6}{2\left(x-2\right)\left(x+2\right)}\)
\(=\dfrac{3x^2+4x+6}{2\left(x-2\right)\left(x+2\right)}\)
c: Khi x=-3 thì \(A=\dfrac{3\cdot\left(-3\right)^2-4\cdot3+6}{2\left(-3-2\right)\left(-3+2\right)}=\dfrac{21}{10}\)
cho bieu thuc A=[x+2/x^2-x+x-2/x^2+x].x^2-1/x^2+2
a) tim dieu kien cua x de gia tri cua bieu thuc A duoc xac dinh
b) tinh gia tri cua bieu thuc A voi x = -200
Rut gon va tinh gia tri bieu thuc
A= (x-4).(x-2)-(x-1).(x-3) tại x= \(1\dfrac{3}{4}\)
Xac dinh gia tri nho nhat cua bieu thuc: T=x^2+2xy+2y^2-2x-2y-2
tinh gia tri cua bieu thuc:
A=x^2+12x+36 tai x=64
B=x^2+4xy+4y^2 khi biet x=2,8; y=3,6
C=(3x-7)^2+10(3x-7)+25 biet x=16
D=8x^3-12x^2+6x-1 tai x=\(\dfrac{-1}{2}\)
tinh gia tri cua bieu thuc A=\(x^3+y^3+3xy\left(x^2+y^2\right)+6x^2y^2\left(x+y\right)\)
cho hai so thuc x,y thoa man x^2+y^2=1. tim gia tri nho nhat cua p=x^6+y^6
tinh nhanh gia tri cua bieu thuc sau voi a=1982
M=(a+4)^2+2(a+4)(6-a)+(6-a)^2
tinh gia tri cua cac bieu thuc sau:
a,x(x-6)-y(6-x) tai x=2006,y=2002
b,5x(x-y)-y(x-y) tai x=60,y=5
cho 1/a+1/b+1/c=0 tinh gia tri cua bieu thuc m=(b+c)/a+(c+a)/b+(a+b)/c
