\(5x\left(3x^2y-2xy^2+1\right)-3xy\left(5x^2-3xy\right)+x^2y^2-10=0\)

\(\Leftrightarrow15x^3y-10x^2y^2+5x-15x^3y+9x^2y^2+x^2y^2-10=0\)

\(\Leftrightarrow5x=10\Leftrightarrow x=2\)

N = -1/10 x² y +4/3xy² -6xy

đúng 100000000000000000000000000% luôn bạn nhé

a,\(\frac{1}{5}x^2y\left(15xy^2-5y+3xy\right)=3x^3y^3-x^2y^2+\frac{3}{5}x^3y^2\)

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

c, \(3x^2+5y-3xy-5x=3x\left(x-y\right)-5\left(x-y\right)\)

\(=\left(3x-5\right)\left(x-y\right)\)

1) 1/5x²y( 15xy² - 5y + 3xy ) = 3x³y³ - x²y² + 3/5x³y²

2) a) 5x³ - 5x = 5x( x² - 1 ) = 5x( x² - 1² ) = 5x( x - 1 )( x + 1 )

b) 3x² + 5y - 3xy - 5x = ( 3x² - 3xy ) + ( 5y - 5x )

                                  = 3x( x - y ) + 5( y - x )

                                  = 3x( x - y ) + 5[ -( x - y ) ]

                                  = 3x( x - y ) - 5( x - y )

                                  = ( 3x - 5 )( x - y )

Bài 1 :

\(15x^2y\left(15xy^2-5y+3xy\right)=3x^3y^3-x^2y^2+\frac{3}{5}x^3y^2\)

Bài 2 : 

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

\(N=\dfrac{2}{5}x^2y+xy^2-3xy+\dfrac{1}{3}xy^2-3xy-\dfrac{1}{2}x^2y\)

\(N=\left(\dfrac{2}{5}x^2y-\dfrac{1}{2}x^2y\right)+\left(xy^2+\dfrac{1}{3}xy^2\right)-\left(3xy+3xy\right)\)

\(N=\left(\dfrac{-1}{10}x^2y\right)+\dfrac{4}{3}xy^2-6xy\)

Thay x = 0,5 và y = -1 vào đa thức N , ta có

\(\dfrac{-1}{10}.\left(0,5\right)^2.\left(-1\right)+\dfrac{4}{3}.0,5.\left(-1\right)^2-6.0,5.\left(-1\right)\)

= \(\dfrac{-1}{10}.0,25.\left(-1\right)+\dfrac{4}{3}.0,5.1-6.0,5.\left(-1\right)\)

\(=0,025+\dfrac{2}{3}-\left(-3\right)\)

= \(\dfrac{443}{120}\)

Vậy đa thức N = \(\dfrac{443}{120}\)

đề thu gọn rồi tính giá trị của đa thức sau tại x=0,5 và y=-1

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

\(3x^2+5x-3xy-5x=x\left(3x+5\right)-x\left(3y+5\right)=x\left(3x-3y\right)=3x\left(x-y\right)\)

\(\frac{1}{5}x^2y\left(15xy^2-5y+3xy\right)\)

\(=\frac{1}{5}x^2y^2\left(15xy-5+3x\right)\)

\(=\frac{1}{5}\left(x.y\right)^2.\left(15xy-5+3x\right)\)

\(=\frac{1}{5}\left(15x^3y^3-5x^2y^2+3x^3y^2\right)\)

làm phần 1 đi bạn

a) 5x² ( 3x² -7x+2)-15x(x-3)

=15x⁴-35x³+10x²-15x²+45x

=15x⁴-35x³-5x²+45x

c) (x+3)(x-3)(x-2)(x+1)

=(x²-9)(x²+x-2x-2)

=(x²-9)(x²-x-2)

=x⁴-x³-2x²-9x²+9x+18

=x⁴-x³-11x²+9x+18

d)(2x+1)²+(4x-1)²+2(2x+1)(4x+1)

=2x²+4x+1-16x²-8x+1

=2x²+4x+1-16x²-8x+1+16x²-4x+8x-2

=2x²+7

e) (2x²-3x)(5x²-2x+1)-10x²(x+3)

=10x⁴ -4x³+2x²-15x³+6x²-3 -10x²-30x

=10x⁴-19x³-2x²-30x-3

thanks bn nka

câu c) bn thíu dấu

a: \(=\left(4xy^2+2xy^2\right)+\left(3x^2y-3x^2y\right)=6xy^2\)

b: \(=xy\left(\dfrac{1}{5}+\dfrac{1}{3}\right)+xy^2\left(\dfrac{4}{3}-\dfrac{2}{5}\right)=\dfrac{8}{15}xy+\dfrac{14}{15}xy^2\)

d: \(=\dfrac{-4}{9}\cdot\dfrac{3}{2}\cdot xy^2\cdot xy^3=-\dfrac{2}{3}x^2y^5\)

\(\left(5x-3xy^2\right)^2\\ =\left(5x\right)^2-2.5z.3xy^2+\left(3xy^2\right)^2\\ =25x^2-30xy^2z+9x^2y^4\)

\(\left(5x-3xy^2\right)^2=25x^2-30x^2y^2+9x^2y^4\)

\(M+N-P=\left(x^2-3xy-2y^2\right)+\left(-5x^2+xy+y^2\right)-\left(-5x^2-4xy-2y^2\right)\\ \Rightarrow x^2-3xy-2y^2-5x^2+xy+y^2+5x^2+4xy+2y^2\\ \Rightarrow x^2+2xy+y^2\)