`#tnvt`
`a)x^2+x+1/2=(x+1/2)^2`
`b)9x^2-12x+4=(3x-2)^2`
`c)4y^2-9x^2=(2y-3x)(2y+3x)`
`d)9y^2-1/4=(3y-1/2)(3y+1/2)`
`e)8x^3+8a^3=(2x+2a)(4x^2-4ax+4a^2)`
`g)64x^3-27y^3=(4x-3y)(16x^2+12xy+9y^2)(\text{Sửa đề})`
Áp dụng HĐT: `a^2+2ab+b^2=(a+b)^2`
`a^2-2ab+b^2=(a-b)^2`
`a^2-b^2=(a-b)(a+b)`
`a^3+b^3=(a+b)(a^2-ab+b^2)`
`a^3-b^3=(a-b)(a^2+ab+b^2)`