Calculating rational numbers skillfully, -1+3-5+7-9+…… -97+99

Calculating rational numbers skillfully, -1+3-5+7-9+…… -97+99

Two by two,
Original formula = 2 + 2 +. + 2 (25)
=2*25
=50

When a is a rational number, calculate | a | + | - a | - (- a) | - [- (- a)] | + | - {- [- (- a)]} |,

|a|+|-a|-|-(-a) |-|-[-(-a)]|+|-{-[-(-a)]}|
=|a|+|a|-|a|-|a|+|a|
=|a|
In the absolute value, no matter how many signs are in front of it, it is equal to | a|

Rational number calculation (important process)
[(- 5) to the power of 2003 * (- 0.2) to the power of 2003 + (- 1) to the power of (2n + 1)] / [3.14 to the power of 2003 - (- 1) to the power of 3652]

={[(-5)*(-0.2)]^2003+(-1)}/(3.14^2003-1)
=[1^2003+(-1)]/(3.14^2003-1)
=[1+(-1)]/(3.14^2003-1)
=0/(3.14^2003-1)
=0
Enough detail

Use 7,3, - 3, - 7 to add, subtract, multiply, divide or multiply to make the result 24 or - 24
Please help, thank you!

[3+(-3)/(-7）]*7=24