`2^2 *5^2 -(2008^0 +8):3^2`

`=4*25-(1+8):9`

`=100-9:9`

`=100-1`

`=99`

`2^3 *5^2 -(2014^0 +8):3^2 +0^23`

`=8*25-(1+8):9+0`

`=200-9:9`

`=200-1`

`199`

`2*3^3 +143:(2016^0 * 6^2 -625:25)`

`=2*27+143:(1*36-25)`

`=54+143:11`

`=54+13`

`=67`

`4*5^2 -3^2 (2018^0 +3^2)`

`=4*25-9(1+9)`

`=100-9*10`

`=100-90`

`=10`

(2)

em nghĩ sẽ vào Vợ chồng a phủ, người lái đò sông đà, Đất nước mà hóa ra là Vợ nhặt =))

`(x+y)^3 +(x-y)^3 `

`=[(x+y)+(x-y)][(x+y)^2 -(x+y)(x-y)+(x-y)^2 ]`

`=(x+y+x-y)[x^2 +2xy+y^2 -(x^2 -y^2 )+x^2 -2xy+y^2 ]`

`=2x(2x^2 +2y^2 -x^2 +y^2 )`

`=2x(x^2 +3y^2 )`

`=2x^3 +6xy^2`

\(\sqrt{x^2+1}-x=3\\ < =>\sqrt{x^2+1}=3+x\\ < =>\left\{{}\begin{matrix}3+x\ge0\\x^2+1=9+6x+x^2\end{matrix}\right.\)

\(< =>\left\{{}\begin{matrix}x\ge-3\\6x=-8\end{matrix}\right.\\ < =>\left\{{}\begin{matrix}x\ge-3\\x=-\dfrac{4}{3}\left(tm\right)\end{matrix}\right.\\ < =>x=-\dfrac{4}{3}\)

đề bài là gì vậy ạ?

a)

`(3x-1)/4+(6x-5)/8=(1-3x)/6`

`<=>18x-6+18x-15=4-12x`

`<=>18x+18x+12x=4+6+15`

`<=>48x=25`

`<=>x=25/48`

b)

`(1-2x)^2 +(x-3)(2x-1)=0`

`<=>1-4x+4x^2 +2x^2 -x-6x+3=0`

`<=>4x^2 +2x^2 -4x-x-6x+1+3=0`

`<=>6x^2 -11x+4=0`

`<=>6x^2 -3x-8x+4=0`

`<=>3x(2x-1)-4(2x-1)=0`

`<=>(3x-4)(2x-1)=0`

`<=>3x-4=0` hoặc `2x-1=0`

`<=>x=4/3` hoặc `x=1/2`

c)

\(\dfrac{1}{x-1}+\dfrac{2x^2-5}{x^3-1}=\dfrac{4}{x^2+x+1}\left(x\ne1\right)\)

`<=>(x^2 +x+1)/((x-1)(x^2 +x+1))+(2x^2 -5)/((x-1)(x^2 +x+1))=(4(x-1))/((x-1)(x^2 +x+1))`

Suy ra

`x^2 +x+1+2x^2 -5=4x-4`

`<=>x^2 +2x^2 +x-4x-5+1+4=0`

`<=>3x^2 -3x=0`

`<=>3x(x-1)=0`

`<=>3x=0` hoặc `x-1=0`

`<=>x=0(tm)` hoặc `x=1(ktm)`