how to make the number 25 using the numbers 3 -4 5 2 8 18

Probably many ways, here's one way where I use all numbers only once:

 

5 x (18 + 2 - 8 + -4 - 3) = 5 x 5 = 25

Here is another: 18 + 8 +2 X (5 -4) -3

                          ( 28 X 1) - 3=25