Mình quên ghi chữ "sai đề" =))

:v dạ chắc bạn ý ghi sai đề á ;-;

Bạn đã làn sai.

`17-{-x-[-x-(-x)]}=-16`

`=>17-[x-(-x+x)]=-16`

`=>17-(x-0)=-16`

`=>17-x=-16`

`=>x=17+16`

`=>x=33`

Vậy `x=33`

`(x+1)+(x+3)+(x+5)+.....+(x+99)=0`

`=>(x+x+.....+x)+(1+3+5+......+99)=0`

`=>50x+(100.50)/2=0` (do từ 1 đến 99 có 50 số nên vì vậy cũng có 50x)

`=>50x+50.50=0`

`=>50(x+50)=0`

`=>x+50=0`

`=>x=-50`

Vậy `x=-50`

`(2x+3)((3x+8)/(2-7x)+1)=(x-5)((3x+8)/(2-7x)+1)`

`ĐK:x ne 7/2`

`pt<=>((3x+8)/(2-7x)+1)(2x+3-x+5)=0`

`<=>((3x+8)/(2-7x)+1)(x+8)=0`

`<=>` $\left[ \begin{array}{l}x+8=0\\\dfrac{3x+8}{2-7x}=-1\end{array} \right.$

`<=>` $\left[ \begin{array}{l}x=-8\\3x+8=7x-2\end{array} \right.$

`<=>` $\left[ \begin{array}{l}x=-8\\4x=10\end{array} \right.$

`<=>` $\left[ \begin{array}{l}x=-8(TM)\\x=\dfrac{5}{2}(TM)\end{array} \right.$

Vậy `S={-8,5/2}`

`a,16(x+4)^{2020}=25(x+4)^{2018}`

`=>16(x+4)^{2020}-25(x+4)^{2018}=0`

`=>(x+4)^{2018}[16(x+4)^2-25]=0`

`=>` $\left[ \begin{array}{l}x+4=0\\16(x+4)^2=25\end{array} \right.$

`=>` $\left[ \begin{array}{l}x=-4\\(x+4)^2=\dfrac{25}{16}\end{array} \right.$

`=>` $\left[ \begin{array}{l}x=-4\\x+4=\dfrac{5}{4}\\x+4=-\dfrac{5}{4}\end{array} \right.$

`=>` $\left[ \begin{array}{l}x=-4\\x=-\dfrac{11}{4}\\x=-\dfrac{21}{4}\end{array} \right.$

Vậy `x=-4` hoặc `x=-11/4` hoặc `x=-21/4`

`4.(3-x)^10=9(3-x)^8`

`=>(3-x)^{8}(4(3-x)^2-9)=0`

`=>` $\left[ \begin{array}{l}3-x=0\\(3-x)^2=\dfrac{9}{4}\end{array} \right.$

`=>` $\left[ \begin{array}{l}x=3\\3-x=\dfrac{3}{2}\\3-x=-\dfrac{3}{2}\end{array} \right.$

`=>` $\left[ \begin{array}{l}x=3\\x=\dfrac{3}{2}\\x=\dfrac{9}{2}\end{array} \right.$

Vậy `x=3` hoặc `x=3/2` hoặc `x=9/2`

`b,(x-1)^{x+3}=(x-1)^{x+1}`

`=>(x-1)^{x+1}[(x-1)^2-1]=0`

`=>` $\left[ \begin{array}{l}x-=1\\x-=-1\end{array} \right.$

`=>` $\left[ \begin{array}{l}x=2\\x=1\\x=0\end{array} \right.$

Vậy `x=0` hoặc `x=1` hoặc `x=2`

Ồ mình có 62 coin :)

The more you run,the fitter you will get.