Sao ko gõ Latex, gõ thế này không nhìn dc

c) \(51,7^2-2.51,7.31,7+31,7^2=\left(51,7-31,7\right)^2\)

a) (x^2+2xy+y^2) : (x+y)

=(x+y)²:(x+y)

=x+y

b) (125x^3+1) : (5x+1)

=(5x+1)(25x²-5x+1):(5x+1)

=25x²-5x+1

c) (x^2-2xy+y^2) : (y-x)

=(x-y)²:(y-x)

=-(x-y)²:(x-y)

=-(x-y)

=-x+y

Bài 1:

a) Mình không hiểu đề cho lắm 

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

   \(=3x\left(x^2-2x+1\right)-2x\left(x^2-9\right)+4x\left(x-4\right)\) 

   \(=3x^3-6x^2+3x-2x^3+18x+4x^2-16x\)  

   \(=x^3-2x^2+5x\)  

c) \(2\left(2x+5\right)^2-3\left(4x+1\right)\left(1-4x\right)\)

   \(=2\left(2x+5\right)^2+3\left(4x+1\right)\left(4x-1\right)\)

    \(=2\left(4x^2+20x+25\right)+3\left(16x^2-1\right)\)

    \(=8x^2+40x+50+48x^2-3\)

    \(=56x^2+40x+47\)

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

   \(=x\left(x^2-16\right)-\left(x^4-1\right)\)

   \(=x^3-16x-x^4+1\)

e) \(\left(y-3\right)\left(y+3\right)\left(y^2+9\right)-\left(y^2+2\right)\left(y^2-2\right)\)

    \(=\left(y^2-9\right)\left(y^2+9\right)-\left(y^4-4\right)\)

    \(=y^4-81-y^4+4\)

    \(=-77\)

a) x² - 2xy + y² - 4m² + 4mn - n² = (x - y)² - [(2m)² -  2.2m.n + n²] = (x - y)² - (2m - n)²

= [(x - y) - (2m - n)][(x - y) + (2m - n)] = (x - y - 2m + n)(x - y + 2m - n)

b) x² - 4x²y² + y² + 2xy = x² + 2xy + y² - 4x²y² = (x + y)² - (2xy)² = (x + y - 2xy)(x + y + 2xy)

c) x⁶ - y⁶ = (x³)² - (y³)² = (x³ - y³)(x³ + y³) = (x - y)(x² + xy + y²)(x + y)(x² - xy - y²)

d) 25 - a² + 2ab - b² = 25 - (a² - 2ab + b²) = 5² - (a - b)² = (5 - a + b)(5 + a - b)

xin lỗi các bạn, đề mink có vấn đề: ý c phải là: x^6 - y^6

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

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

\(=3x\left(x^2-2x+1\right)-2x\left(x^2-9\right)+4x^2-16x=3x^3-6x^2+3x-2x^3+18x+4x^2-16x\)\(=x^3-2x^2+5x\)

c) \(2\left(2x+5\right)^2-3\left(4x+1\right)\left(1-4x\right)=2\left(4x^2+20x+25\right)+3\left(16x^2-1\right)\)

\(=8x^2+40x+50+48x^2-3=56x^2+40x+47\)

d) \(x\left(x+4\right)\left(x-4\right)-\left(x^2+1\right)\left(x^2-1\right)=x\left(x^2-16\right)-x^4+1=x^3-x^4-16x+1\)

e) \(\left(y-3\right)\left(y+3\right)\left(y^2+9\right)-\left(y^2+2\right)\left(y^2-2\right)=\left(y^2-9\right)\left(y^2+9\right)-y^4+4=y^4-81-y^2+4=-77\)

Khủng bố

a ) \(2\left(x-1\right)^2-4\left(3+x^2\right)+2x\left(x-5\right)\)

\(=2.\left(x^2-2.x.1+1^2\right)-12-4x^2+2x^2-10x\)

\(=2x^2-4x+2-12-4x^2+2x^2-10x\)

\(=-14x-10\)

1:a.(2ab^2):c=(2.4.-6):12

                  =(-48):12

                  = - 4    

 b.[(-25).(-27).(-x)]:y= [(-25).(-27).(-4)]:-9

                            = (-2700): -9

                            = 300

 c.(a^2 - b^2):(a+b).(a-b) = (5^2 - (-3)^2):(5+(-3)).(5 - (-3)

                                    = 64