What is the speed of a particle whose momentum is 300mc Sho

What is the speed of a particle whose momentum is 3.00mc ?

Show equations and explain variables please & thank you.

here by using relativistic momentum

P = m *v / sqrt( 1 - v^2 / c^2 )

P = 3.00 m* c

then by solving both equation

3 * c * m = m * v / sqrt( 1 - v^2 / c^2)

1 - v^2 / c^2 = v^2 / 9c^2

9c^2 - 9v^2 = v^2

9c^2 = 10v^2

v = sqrt( 9 / 10) * c

the velcoity is sqrt( 9 / 10) * c