\(A=\dfrac{x^2-3x+3}{x^2-2x+1}=\dfrac{\dfrac{3}{4}\left(x^2-2x+1\right)+\dfrac{1}{4}\left(x^2-6x+9\right)}{x^2-2x+1}=\dfrac{3}{4}+\dfrac{\dfrac{1}{4}\left(x-3\right)^2}{\left(x-1\right)^2}\)
MinA là 3/4 khi x=3
a/ tìm Min P(x) = \(\dfrac{2x^2-2x+3}{x^2-x+2}\)
b/ tìm Max Q(x) = \(\dfrac{3x^2+17}{x^2+4}\)
a,\(\dfrac{x^3+2x}{x^3+1}+\dfrac{2x}{x^2-x+1}+\dfrac{1}{x+1}\)
b,\(\dfrac{1-3x}{2x}+\dfrac{3x-2}{2x-1}+\dfrac{3x-2}{2x-4x^2}\)
B1: A=\(\left(\dfrac{2-3x}{x^2+2x-3}-\dfrac{x+3}{1-x}-\dfrac{x+1}{x+3}\right):\dfrac{3x+12}{x^3-1}\)
a) Rút gọn
b) Tìm x thuộc Z để A nguyên
c) Tính A với x=-2; x=-3
d) Tìm x dể A=1
B2: Phân tích thành nhân tử
a) x2-2xy-4+y2
b) x2-4x+3
c) 9x2(x-y)-x+y
B3: Rút gọn
a) (x-2)3-(x+2)3-(x-1)(x2+x+1)
b) (5x+3y)(5x-3y)+(4x-3y)2
B4: P(x)=x4+x3+mx2-3x+5
a) Khi m=4, thực hiện phép chia P(x) cho x2-x+1
b) Tìm m để P(x)⋮(x-1)
Cho a>0. Tìm min P biết: \(P=a+\dfrac{2}{a+1}+3\); min X biết: \(X=\dfrac{a^2+1}{a-1}\)
Giải phương trình :
a,\(\dfrac{2}{x^2+3x+2}+\dfrac{1}{x^2+5x+6}=\dfrac{1}{x^2-3x+2}\)
b, \(\dfrac{2x+3}{x^2+3x+2}+\dfrac{6}{x^2-x-6}=\dfrac{2x-2}{x^2-2x-3}\)
1.giải pt
a)\(\dfrac{16-x}{4}=\dfrac{2x+1}{3}\)
b)(2x+3)(1-3x)=9x\(^2\)-1
c)\(\dfrac{2x}{x+1}+\dfrac{x-1}{x}=\dfrac{2x^2+3x-1}{x^2+x}\)
a) Tìm min A biết \(A=\dfrac{2x^2-16x+41}{x^2-8x+22}\)
b) Tìm min B biết \(B=\dfrac{x^2-4x+1}{x^2}\)
c) Tìm min C biết \(C=\dfrac{4x^2-6x+3}{\left(2x-1\right)^2}\)
d) Tìm max D biết \(D=\dfrac{x^2}{x^4+1}\)
Tìm
Min A= 3x^2+2x+7/x^2+2x+3
Max B= 2x^2-16x+29/x^2-6x+10
Min C = 6x^2-14x+29/x^2-2x+5
Max D = 5x^2+2x+2/x^2+x+1
Giải các phương trình sau:
1. \(a,\dfrac{6}{x-1}-\dfrac{4}{x-3}=\dfrac{8}{2x-6}\)
\(b,\dfrac{1}{x-2}+\dfrac{5}{x+1}=\dfrac{3}{2-x}\)
\(c,\dfrac{3x}{x-2}-\dfrac{x}{x-5}=\dfrac{3x}{\left(x-2\right)\left(5-x\right)}\)
2. \(a,\left(x+2\right)\left(3-4x\right)=x^2+4x+4\)
\(b,2x^2-6x+1\)
