Question

a) (11 - x) : (-5) = 15

b) (2x + 3)^2022 ) . ( -7x + 84) = 0

c) (x - 3) (x + 1) < 0

Answer 1

`(11-x):(-5)=15`

`=> 11-x=-75`

`=> x=86`

Vậy `x = 86`

`((2x+3)^2022) . (-7x+84)=0`

`=> (2x+3)^2022 = 0` hoặc `-7x + 84 = 0`

`=> 2x+3=0` hoặc `-7x = -84`

`=> x = -3/2` hoặc `x = 12`

Vậy `x = -3/2` hoặc `x = 12`

`(x-3)(x+1) < 0`

Ta có: `x - 3 < x + 1`

nên: `x - 3 < 0` và `x + 1 > 0`

`=> x < 3 và x > -1`

`=> -1 < x < 3`

Vậy `-1 <x < 3`

Answer 2

#\(N\)

`a, (11-x)`\(\div\)`(-5)=15`

`11-x=15.-5`

`11-x=-75`

`x=11-(-75)`

`x=11+75=86`

`b, (2x-3)^2022.(-7x+84)=0`

`=>`\(\left\{{}\begin{matrix}\left(2x-3\right)^{2022}=0\\\left(-7x+84\right)=0\end{matrix}\right.\)

`=>` \(\left\{{}\begin{matrix}2x-3=0\\-7x+84=0\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}2x=3+0\\-7x=0-84\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}2x=3\\-7x=-84\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}x=3\div2\\x=-84\div-7\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}x=\dfrac{3}{2}\\x=12\end{matrix}\right.\)

`c, (x-3) (x+1) <0`

`-> (x-3) < x+1`

`-> (x-3)<0 , (x+1)>0`

`-> x < 3 , x> (-1)`

`-> 3 > x > -1`