Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(A=\left(2x-2\right)^2-4x\left(x-2\right)+46\)
\(\Leftrightarrow A=4x^2-8x+4-4x^2+8x+46\)
\(\Leftrightarrow A=50\)
Lời giải:
$(2x+3)^2+(2x+5)^2=4x^2+12x+9+4x^2+20x+25$
$=8x^2+32x+34$
\(=\dfrac{2a\left(a-b\right)}{a\left(c+d\right)-b\left(c+d\right)}=\dfrac{2a\left(a-b\right)}{\left(a-b\right)\left(c+d\right)}=\dfrac{2a}{c+d}\)
\(\left(x^2-2\right)\left(1-x\right)+\left(x+3\right)\left(x^2-3x+9\right)\)
\(=\left(x^2-x^3-2+2x\right)+\left(x^3+3^3\right)\)
\(=x^2-x^3-2+2x+x^3+27\)
\(=\left(-x^3+x^3\right)+x^2+2x+\left(-2+27\right)\)
\(=x^2+2x+25\)
Ta có: \(\left(a+2\right)^2-\left(a+2\right)\left(a-2\right)\)
\(=\left(a+2\right)\left(a+2-a+2\right)\)
\(=\left(a+2\right)\cdot4=4a+8\)
\(B=\dfrac{\left|x^3-3x^2+3x-1\right|}{x^3-3x^2+x}\)
\(=\dfrac{\left|\left(x-1\right)^3\right|}{x\left(x^2-2x+1\right)}\)
\(=\dfrac{\left|\left(x-1\right)^3\right|}{x\left(x-1\right)^2}=\pm\dfrac{x-1}{x}\)
\(B=\dfrac{\left|x^3-3x^2+3x-1\right|}{x^2-2x^3+x}\)
\(B=\dfrac{\left|x^3-3\cdot x^2\cdot1+3\cdot x\cdot1^2-1^3\right|}{x\left(x^2-2x+1\right)}\)
\(B=\dfrac{\left|\left(x-1\right)^3\right|}{x\left(x-1\right)^2}\)
Khi \(x< 1,x\ne0\)
\(B=\dfrac{1-x}{x}\)
Khi \(x>1\)
\(B=\dfrac{x-1}{x}\)