khai triển hđt 4x^2 – 9x^2 x^2 – 4x + 4 26/08/2021 Bởi Samantha khai triển hđt 4x^2 – 9x^2 x^2 – 4x + 4
khai triển hđt sau: `4x^2 – 9x^2` `=(2x)^2 – (3x)^2` `=(2x-3x)(2x+3x)` `x^2 – 4x + 4` `=x^2 – 2. 2. x + 2^2` `=(x-2)^2` Bình luận
$x^2 – 4x + 4$
$=(x-2)^2$
$4x^2−9x^2$
$=(2x)^2−(3x)^2$
$=(2x−3x)(2x+3x)$
khai triển hđt sau:
`4x^2 – 9x^2`
`=(2x)^2 – (3x)^2`
`=(2x-3x)(2x+3x)`
`x^2 – 4x + 4`
`=x^2 – 2. 2. x + 2^2`
`=(x-2)^2`