Question

Answer 1

`8x.(-5-x)=0`

`=>`\(\left[{}\begin{matrix}8x=0\\-5-x=0\end{matrix}\right.\)

`=>`\(\left[{}\begin{matrix}x=0:8\\x=-5-0\end{matrix}\right.\)

`=>`\(\left[{}\begin{matrix}x=0\\x=-5\end{matrix}\right.\)

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`(8+x).(6-x)=0`

`=> 8+x=0`

`x=0-8`

`x=-8`

`=> 6-x=0`

`x=6-0`

`x=6`

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`-1005 . (x+2)=0`

`x+2=0:(-1005)`

`x+2=0`

`x=0-2`

`x=-2`

Answer 2

a) 8.x.(-5 - x) = 0

8.x = 0 hoặc -5 - x = 0

*) 8.x = 0

x = 0

*) -5 - x = 0

x = -5

Vậy x = -5; x = 0

b) (8 + x)(6 - x) = 0

8 + x = 0 hoặc 6 - x = 0

*) 8 + x = 0

x = -8

*) 6 - x = 0

x = 6

Vậy x = -8; x = 6

c) -1005.(x + 2) = 0

x + 2 = 0

x = 0 - 2

x = -2

Vậy x = -2