a) 2x(y-2009)+5y(y-2009)
=(y-2009)(2x+5y)
b) 35x(y-8)-14y(8-y)
=35x(y-8)+14y(y-8)
=7(y-8)(5x+2y)
c) 15x^2 +10xy =5x(3x+2y)
d)24x-18y+30= 6(4x+3y+10)
e) x^2 +14x+49
= x^2 +2.7.x+ 7^2
=(x+7)^2
i) x^2 -x - y^2 - y
=(x^2 -y^2)-(x+y)
=(x-y)(x+y)-(x+y)
=(x+y)(x-y-1)
k) x^2 -2xy+y^2 -z^2
=(x^2 -2xy+y^2) -z^2
=(x-y)^2 -z^2
= (x-y-z)(x-y+z)
a) \(2x\left(y-2009\right)+5y\left(y-2009\right)\) \(=\left(y-2009\right)\left(2x+5y\right)\)
b) \(35x(y-8)-14y(8-y)\) \(=35x\left(y-8\right)+14y\left(y-8\right)\)
\(=\left(y-8\right)\left(35x+14y\right)\)
\(=\left(y-8\right).7\left(5x+2y\right)\)
c) \(15x^2+10xy=5x\left(3x+2y\right)\)
d) \(24x-18y+30=3\left(8x-6y+10\right)\)
e) \(x^2+14x+49=x^2+2.7.x+7^2\)
\(=\) \((x+7)^2\)
g) \(27x^3+y^3\) \(=\left(3x+y\right)\left(9x^2-3xy+y^2\right)\)
h) \(8x^3-\dfrac{1}{125}y^3=\left(2x-\dfrac{1}{5}y\right)\left(4x^2+\dfrac{2}{5}xy+\dfrac{1}{25}y^2\right)\)
i) \(x^2-x-y^2-y=\left(x^2-y^2\right)-\left(x+y\right)\)
\(=\left(x-y\right)\left(x+y\right)-\left(x+y\right)\)
\(=\left(x+y\right)\left(x-y-1\right)\)
k) \(x^2-2xy+y^2-z^2=\left(x^2-2xy+y^2\right)-z^2\)
\(=\left(x-y\right)^2-z^2\)
\(=\left(x-y-z\right)\left(x-y+z\right)\)
- HỌC TỐT NHA BẠN YÊU ^^ -
