|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.
Answer:
Option (3).
Step-by-step explanation:
Option (1).
3(x - 1) = x + 2(x + 1) + 1
3x - 3 = x + 2x + 2 + 1
3x - 3 = 3x + 3 [Not True]
Therefore, this equation is not an identity.
Option (2).
x - 4(x + 1) = -3(x + 1) + 1
x - 4x - 4 = -3x - 3 + 1
-3x - 4 = -3x - 2 [Not true]
Therefore, this equation is not an identity.
Option (3).
2x + 3 = 
2x + 3 = 2x + 1 + 2
2x + 3 = 2x + 3 [True]
Therefore, this equation is an identity.
Option (4).

3x - 1.5 = 3x + 3 - x - 2
3x - 1.5 = 2x + 1 [Not true]
Therefore, this equation is not an identity.
Answer:
274560
Step-by-step explanation:
We can "choose" one of the 66 athletes for the gold medal. That athlete can't win any other medals, so there are 65 athletes left.
We can then "choose" one of the 65 athletes left for the silver medal. That athlete can't win any other medals, so there are 64 athletes left.
We can then "choose" one of the 64 athletes left for the bronze medal.
That leaves us with 66 possible choices * 65 possible choices * 64 possible choices=274560 possible choices