tính a) a^6-b^3 b) x^4-y^4 c) (x/3-6y) ³ 05/07/2021 Bởi Parker tính a) a^6-b^3 b) x^4-y^4 c) (x/3-6y) ³
`#DyHungg` `a) a^6-b^3` `=(a^2)^3-(b)^3` `=(a^2-b)(a^4+a^2b+b^2)` …………….. `b) x^4-y^4` `=(x^2)^2-(y^2)^2` `=(x^2-y^2)(x^2+y^2)` …………. `c) (x/3-6y)^3` `=(x^3/27)-3.(x^2/9).6y+3.x/3.36y^2-216y^3` `=(x^3/27)-2x^2y+36xy^2-216y^3` Bình luận
a)$\begin{array}{l} {a^6} – {b^3}\\ = {\left( {{a^2}} \right)^3} – {b^3}\\ = \left( {{a^2} – b} \right)\left( {{a^4} + {a^2}b + {b^2}} \right) \end{array}$ b) $\begin{array}{l} {x^4} – {y^4}\\ = \left( {{x^2} – {y^2}} \right)\left( {{x^2} + {y^2}} \right)\\ = \left( {x – y} \right)\left( {x + y} \right)\left( {{x^2} + {y^2}} \right) \end{array}$ c) $\begin{array}{l} {\left( {\dfrac{x}{3} – 6y} \right)^3} = \dfrac{{{x^3}}}{9} – 3.\dfrac{{{x^2}}}{9}.6y + 3.\dfrac{x}{3}.36{y^2} – 216{y^3}\\ = \dfrac{{{x^3}}}{9} – 2{x^2}y + 36x{y^2} – 216{y^3} \end{array}$ Bình luận
`#DyHungg`
`a) a^6-b^3`
`=(a^2)^3-(b)^3`
`=(a^2-b)(a^4+a^2b+b^2)`
……………..
`b) x^4-y^4`
`=(x^2)^2-(y^2)^2`
`=(x^2-y^2)(x^2+y^2)`
………….
`c) (x/3-6y)^3`
`=(x^3/27)-3.(x^2/9).6y+3.x/3.36y^2-216y^3`
`=(x^3/27)-2x^2y+36xy^2-216y^3`
a)$\begin{array}{l} {a^6} – {b^3}\\ = {\left( {{a^2}} \right)^3} – {b^3}\\ = \left( {{a^2} – b} \right)\left( {{a^4} + {a^2}b + {b^2}} \right) \end{array}$
b)
$\begin{array}{l} {x^4} – {y^4}\\ = \left( {{x^2} – {y^2}} \right)\left( {{x^2} + {y^2}} \right)\\ = \left( {x – y} \right)\left( {x + y} \right)\left( {{x^2} + {y^2}} \right) \end{array}$
c)
$\begin{array}{l} {\left( {\dfrac{x}{3} – 6y} \right)^3} = \dfrac{{{x^3}}}{9} – 3.\dfrac{{{x^2}}}{9}.6y + 3.\dfrac{x}{3}.36{y^2} – 216{y^3}\\ = \dfrac{{{x^3}}}{9} – 2{x^2}y + 36x{y^2} – 216{y^3} \end{array}$