`Đáp án + Giải thích các bước giải:`

`1` 

`(x−1)(x^2+x+1)+(x+2)(2−x)=5`

`(x−1)(x2+x+1)=x^3−1`

`(x+2)(2−x)=4−x^2`

`x^3−1+4−x^2=5`

`x^3−x^2+3=5`

`x^3−x^2−2=0`

`x≈1.70`

`2`

`(2x+1)(4x^2−2x+1)−8x(x+2)=17`

`(2x+1)(4x^2−2x+1)=8x3+1`

`−8x(x+2)=−8x^2−16x`

`8x^3+1−8x^2−16x=17`

`x^3−x^2−2x−2=0`

`x≈2.27`