\(2x^2\left(x-2\right)-2x\left(x-1\right)\left(x+1\right)=2x^3-4x^2-2x^3+2x=-4x^2+2x=-2x\left(2x-1\right)\)

\(2x^2\left(x-2\right)-2x\left(x-1\right)\left(x+1\right)\)

\(=2x^3-4x^2-2x\left(x^2-1\right)\)

\(=2x^3-4x^2-2x^3+2x=-4x^2+2x\)

2ax^2-a(1+2x^2)-[a-x(x+a)]

=2ax²-2ax²+a+x²-ax+a

=(2ax²-2ax²)-(a+a)+ax+x²

=0-2a+ax+x²

=x²+ax-2a

\(A=\left(2x-1\right)^2-5x\left(x-1\right)+2\left(x+1\right)\left(x-2\right)\)

\(=4x^2-4x+1-5x^2+5x+2\left(x^2-x-2\right)\)

\(=x^2-x-3\)

\(:P=5x(x-3)(x+3)-(2x-3)^2+34x(x+2)-5(x+2)^3+25x-1\)

\(P=5x(x^2-9)-(4x^2-12x+9)+34x^2+68x-5(x^3+6x^2+12x+8)+25-1\)

\(P=5x^3-45x-4x^2+12x-9+34x^2+68x-5x^3-30x^2-60x-40+25-1\)

\(P=(5x^3-5x^3)+(34x^2-4x^2-30x^2)+(12x-45x++68x+25x-60x)-(9+1)\)

\(P=-10\)

Ta có 2x(2x + 1)² - 3x(x + 3)(x - 3) - 4x(x + 1)²

= 2x(4x² + 4x + 1) - 3x(x² - 9) - 4x(x² + 2x + 1) 

= 8x³ + 8x² + 2x - 3x³ + 27x - 4x³ - 8x² - 4x

= 8x³ - 3x³ - 4x³ + 8x² - 8x² + 2x + 27x - 4x

= x³ + 25x 

a oi hinh nhu sai r con +16x² nua co a , anh tinh lai ho e duoc kh

Kiều Trinh Vũ ko có + 16x² nhá vì 8x² - 8x² = 0 nhá 

Lời giải:
$(2x+3)^2+(2x+5)^2=4x^2+12x+9+4x^2+20x+25$

$=8x^2+32x+34$

=> B= (2x+1)(2x+1-2x+1)

=> B=(2x+1).2 =>B=4x+2

\(\left(2x+1\right)^2-\left(2x+1\right)\left(2x-1\right)\)

\(=4x^2+4x+1-4x^2+1=4x+2=2\left(x+2\right)\)

chúc bn hc tốt ^^

Ta có B=(2x+1)2-(2x+1)(2x-1)

=>B=4x^2+1-4x^2-2x+2x+1

=>B=(4x^2-4x^2)+(-2x+2x)+(1+1)

=>B=2

A²=x+\(\sqrt{2x-1}\)+x-\(\sqrt{2x-1}\)- 2\(\sqrt{\left(x+\sqrt{2x-1}\right)\left(x-\sqrt{2x-1}\right)}\)

A²=2x-2\(\sqrt{x^2-2x+1}\)

A²=2x-2(x-1)=1

=>A=1(vì a>0)

Ta có: \(A=\sqrt{x+\sqrt{2x-1}}-\sqrt{x-\sqrt{2x-1}}\)   \(\left(ĐK:x\ge\frac{1}{2}\right)\)

   \(\Leftrightarrow A\sqrt{2}=\sqrt{2x+2\sqrt{2x-1}}-\sqrt{2x-2\sqrt{2x-1}}\)

   \(\Leftrightarrow A\sqrt{2}=\sqrt{2x-1+2\sqrt{2x-1}+1}-\sqrt{2x-1-2\sqrt{2x-1}+1}\)

   \(\Leftrightarrow A\sqrt{2}=\sqrt{\left(\sqrt{2x-1}+1\right)^2}-\sqrt{\left(\sqrt{2x-1}-1\right)^2}\)

   \(\Leftrightarrow A\sqrt{2}=\sqrt{2x-1}+1-\sqrt{2x-1}+1\)

   \(\Leftrightarrow A\sqrt{2}=2\)

   \(\Leftrightarrow A=\sqrt{2}\)