What is the solution set for [-x]=10

X = -10

Because it is the "absolute value" of "10"

Here's why

-X - 10 = 0, right ?

So, now we have to add a positive 10 to each of our sides to get one step closer to our answer

-X + 10 = 0 ⬅️cancel this
0 + 10 = 10 ⬅️keep this

We can multiply by a negative 1 (-1 )

10(-1) = -10
0(-1) = -0

So that's how we found out that X = -10

3(x + 10) + 6 = 3(x + 12)
3x + 30 + 6 = 3x + 36
3x + 36 = 3x + 36
L.H.S. = R.H.S

As both sides, are equal, equation must have "Many Infinite Solutions"

Hope this helps!