Question

a) (x + 2)² - (x + 3)(x - 3) + 10
b) (x + 5)(x² - 5x + 25) - x(x - 4)² + 16x
c) (x - 2y)³- (x + 2y)(x² - 2xy + 4y²) + 6x²y
giúp tớ với ạ, nhanh nha <33

Answer 1

a)

\(=x^2+4x+4-x^2+9+10=\left(x^2-x^2\right)+4x+\left(4+9+10\right)=4x+23\)

b)

\(x^3+125-x\left(x^2-8x+16\right)+16x=x^3+125-x^3+8x^2-16x=\left(x^3-x^3\right)+8x^2-16x+125=8x^2-16x+125\)

c)

\(x^3-6x^2y+12xy^2-8y^3-x^3-8y^3+6x^2y=\left(x^3-x^3\right)+\left(-6x^2y+6x^2y\right)+12xy^2+\left(-8y^3-8y^3\right)=12xy^2-16y^3\)

Answer 2

A, X = \(-5\dfrac{3}{4}\)

 

B, \(X=-\dfrac{\sqrt{125i}}{\sqrt{8}}\) 

     \(X=\dfrac{\sqrt{125i}}{\sqrt{8}}\) 

C, 

C1: Rút gọn biểu thức

\([-8]y^3+[8x-8]y^2+[[-2]x^2-4x]y-2x^2\) 

C2: Phân tích thành nhân tử

[ \(-2\) ] [\(4y^3-4xy^2+4y^2+x^2y+2xy+x^2\) ]

 

#нᴀzuκι?

Answer 3

\(a,\left(x+2\right)^2-\left(x+3\right)\left(x-3\right)+10\)
\(=x^2+4x+4-x^2+9+10\)
\(=4x+23\)
_______________________________
\(b,\left(x+5\right)\left(x^2-5x+25\right)-x\left(x-4\right)^2+16x\)
\(=x^3+125-x\left(x^2-4x+4\right)+16x\)
\(=x^3+125-x^3+4x^2-4x+16x\)
\(=4x^2+12x+125\)
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\(c,\left(x-2y\right)^3-\left(x+2y\right)\left(x^2-2xy+4y^2\right)+6x^2y\)
\(=x^3-6x^2y+12xy^2-8y^3-x^3-8y^3+6x^2y\)
\(=-16y^3+12xy^2\)