|a| = b gives
a =b or a = -b
so,
|-x| = -10
gives
-x = -10 or -x = 10
x = 10, -10
now let us verify,
when x = 10, |-10| = +10 and it is not = -10
so, x= 10 is NOT a solution.
when x = -10, |-(-10)| = |10| = 10 and it is not = -10
so, x= -10 is NOT a solution.
hence, this equation does not have a solution.
If we know that |...| can never be negative, we can directly deduce that this equation does not have any solution.
If you would like to evaluate 6 * [5 * (3 - 9) - 1] + 2 / 7 * (8 - 2) + 4, you can calculate this using the following steps:
6 * [5 * (3 - 9) - 1] + 2 / 7 * (8 - 2) + 4 = 6 * [5 * (-6) - 1] + 2/7 * 6 + 4 = 6 * [- 30 - 1] + 12/7 + 4 = 6 * [- 31] + 12/7 + 4 = - 186 + 12/7 + 4 = - 182 + 12/7 = - 1274/7 + 12/7 = - 1262/7
The correct result would be - 1262/7.
The answer is 4 square root 80