Bài 1 : Rút gọn biểu thức sau
a ) xy ( x^5 – y ³ ) – x ² y ( x^4 – y ³)
b ) x ³ y^4 ( x ² – y ³ ) – x ² y ³ ( x^4 – y^4)
c ) 90 . 10^n – 10^n+ ² + 10^n+1
d ) y ( x^n-1 + y^n-1 ) – x^n-1 ( x + y )
Bài 1 : Rút gọn biểu thức sau
a ) xy ( x^5 – y ³ ) – x ² y ( x^4 – y ³)
b ) x ³ y^4 ( x ² – y ³ ) – x ² y ³ ( x^4 – y^4)
c ) 90 . 10^n – 10^n+ ² + 10^n+1
d ) y ( x^n-1 + y^n-1 ) – x^n-1 ( x + y )
$a)$
$xy ( x^5 – y ³ ) – x ² y ( x^4 – y ³)$
$=x^6y-xy^4-x^6y+x^2y^4$
$=-xy^4+x^2y^4$
$b)$
$x ³y^4(x²-y ³)-x ²y³(x^4-y^4)$
$=x^5y^4-x^3y^7-x^6y^3+x^2y^7$
$c)$
$90.10^n-10^{n+2}+10^n+1$
$=900^n-10^{n+2}+10^n+1$
$d)$
$y ( x^{n-1}+ y^{n-1} ) – x^{n-1} ( x + y )$
$=yx^{n-1}+y^n-x^n-x^{n-1}y$
$=y^n-x^n$
xin hay nhất ạ
`#DyHungg`
`a) xy(x^5-y^3)-x^2y(x^4-y^3)`
`=x^6y-xy^4-x^6y+x^2y^4`
`=-xy^4+x^2y^4`
……..
`x^3y^4(x^2-y^3)-x^2y^3(x^4-y^4)`
`=x^5y^4-x^3y^7-x^6y^3+x^2y^7`
……………….
`90.10^n-10^(n+2)+10^(n+1)`
`=900^n-10^(n+2)+10^(n+1)`
……………..
`y(x^(n-1)+y^(n-1))-x^(n-1)(x+y)`
`=x^(n-1)y+y^(n-1+1)-x^(n-1+1)-x^(n-1)y`
`=y^n-x^n`