v^2=u^2 + 2as u=12 a=-3 s = 18 Find v

First we can plug in the values we already know into the equation
we would get:
V² = 12² + (2 x -3 x 18)
then we would seperate the two multiplications on the right hand side12 x 12 = 144 2 x -3 x 18 = -6 x 18 = -108
Then we can plug these answers back into the equation
v²= 144 -108
simple subtraction
v² = 36
What is the square root of 36?
V= 6