phân tích: a) 2x^2 -6x b) 2x^2 – 18 c) x^3 + 3x^2 + x + 3 d) x^2 – y^2 + 6y – 9 24/10/2021 Bởi Valentina phân tích: a) 2x^2 -6x b) 2x^2 – 18 c) x^3 + 3x^2 + x + 3 d) x^2 – y^2 + 6y – 9
a) ${ 2x^2-6x}$ ${ = 2x.(x-3)}$ b) ${ 2x^2 – 18}$ ${ = 2.(x^2-9)}$ ${ = 2.(x^2-3^2)}$ ${ = 2.(x-3).(x+3)}$ c) ${ x^3 + 3x^2 + x + 3}$ ${ =x^2.(x+3)+(x+3)}$ ${ = (x^2+1).(x+3)}$ d) ${ x^2 – y^2 + 6y – 9}$ ${ = x^2-(y^2-6y+9)}$ ${ = x^2-(y^2-2.3.y+3^2)}$ ${ = x^2-(y-3)^2}$ ${ = (x-y+3).(x+y-3)}$ Bình luận
`#Xray` `a) 2x²-6x=2x(x-3)` `b)2x²-18=2(x²-9)=2(x-3)(x+3)` `c)x³+3x²+x+3` `=x²(x+3)+(x+3)` `=(x+3)(x²+1)` `d)x²-y²+6y-9` `=x²-(y²-6y+9)` `=x²-(y-3)²` `=(x-y+3)(x+y-3)` Bình luận
a) ${ 2x^2-6x}$
${ = 2x.(x-3)}$
b) ${ 2x^2 – 18}$
${ = 2.(x^2-9)}$
${ = 2.(x^2-3^2)}$
${ = 2.(x-3).(x+3)}$
c) ${ x^3 + 3x^2 + x + 3}$
${ =x^2.(x+3)+(x+3)}$
${ = (x^2+1).(x+3)}$
d) ${ x^2 – y^2 + 6y – 9}$
${ = x^2-(y^2-6y+9)}$
${ = x^2-(y^2-2.3.y+3^2)}$
${ = x^2-(y-3)^2}$
${ = (x-y+3).(x+y-3)}$
`#Xray`
`a) 2x²-6x=2x(x-3)`
`b)2x²-18=2(x²-9)=2(x-3)(x+3)`
`c)x³+3x²+x+3`
`=x²(x+3)+(x+3)`
`=(x+3)(x²+1)`
`d)x²-y²+6y-9`
`=x²-(y²-6y+9)`
`=x²-(y-3)²`
`=(x-y+3)(x+y-3)`