Question

l-3nl-2=4

Answer 1

lxl=-x only if x<0
thus after squaring we get 9n2=36
n2=36/9
n=-2 as lxl=-x will take negative value

Answer 2

It's almost the same thing here. Get rid of that -2, by adding 2 to both sides
\[\left| -3n \right|=6\]
Now, you know that -3n = -1*3n
And, by properties of absolute values, |a*b|=|a|*|b|,
\[\left| -1\right|\left| 3n \right|=6\]
The absolute value of -1 is, of course, 1, so you can scratch it out since it's multiplying. And by the same property of abs. value, you can separate 3n
\[\left| 3\right|\left| n \right|=6\]
The absolute value of 3 is, of course, 3. Now divide by 3 on both sides,
\[\left| n \right|=6/3\]
\[\left| n \right|=2\]
You can again do it analytically, n={-2,2} since the absolute values of those two numbers is 2, or you can square and take the square root
\[\left| n \right|^2=4\]
And since \[\left| x \right|^2=x^2\],
You can get rid of that abs. value:
\[n^2=4\]
\[n=\pm \sqrt{4}\]
\[n=\pm 2\]

Answer 3

thanks