Question

a,177-15x=2³.3²

b,x chia hết 6 và x<31

c,x ∈ ƯC 20 và x > 9

d,x(x-15)=0

Answer 1

`a, 177 - 15x = 2^3 . 3^2`

`=> 177 - 15x = 8 . 9`

`=> 177 - 15x = 72`

`=> 15x = 177 - 72`

`=>15x=105`

`=>x=105:15`

`=>x=7`

Vậy: `x=7`

`b,` Ta có:

`x\vdots 6`

`-> x \in B(6)={0;6;12;18;24;30;...}`

Mà `x < 31` nên `x = {0;6;12;18;24;30}`

Vậy: `x = {0;6;12;18;24;30}`

Answer 2

`d, x(x-15)=0`

`=> [(x = 0),(x-15=0):}`

`=> [(x = 0),(x=0+15):}`

`=> [(x=0),(x=15):}`

Vậy: `x=0;x=15`

Answer 3

`a, 177 - 15x =2^3 * 3^2 `

`=> 177 - 15x = 8 * 9`

`=> 177 - 15x = 72`

`=> 15x = 177 - 72`

`=> 15x = 105`

`=> x = 105 : 15`

`=> x = 7`

Vậy `x = 7`

`b, x \vdots 6 `và `x < 31`

`x \vdots 6` thì `=> x \in B(6) = {0;6;12;18;24;30;36;...}`

Mà `x < 31`

`=> x \in {0;6;12;18;24;30}`

\(d,x\left(x-15\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x=0\\x-15=0\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}x=0\\x=15\end{matrix}\right.\)

Vậy `x \in {0;15}`

`c,` Xem lại đề