1, Viết các đa thức sau thành tích :
a, x3+8y3
b, a6-b3
c, 8y3-125
d, 8x3+27
* giúp mk với :
a) \(x^3 + 8y^3\)
\(=\left(x+2y\right)\left(x^2-2xy+4y^2\right)\)
b) \(a^6-b^6\)
\(=\left(a^3-b^3\right)\left(a^3+b^3\right)\)
c) \(8y^3-125\)
\(=\left(2y-5\right)\left(4y^2+10y+25\right)\)
d) \(8x^3+27\)
\(=\left(2x+3\right)\left(4x^2-6x+9\right)\)
a) \(x^3+8y^3\)
\(=x^3+\left(2y\right)^3\)
\(=\left(x+2y\right)\left(x^2-2xy+y^2\right)\)
b) \(a^6-b^3\)
\(=\left(a^2\right)^3-b^3\)
\(=\left(a^2-b\right)\left(a^4+a^2b+b^2\right)\)
c) \(8y^3-125\)
\(=\left(2y\right)^3-5^3\)
\(=\left(2y-5\right)\left(4y^2+10y+25\right)\)
d) \(8x^3+27\)
\(=\left(2x\right)^3+3^3\)
\(=\left(2x+3\right)\left(4x^2-6x+9\right)\)
