elastic collision 2 dimension unequal masses not at rest

grrrphysics

Please help! i know how to do a elastic collisions in 1 dimension, but the 2D is too confusing...here is my problem:

You have a blue ball with a mass of 1.5 kg moving with a speed of 4.5 m/s in a direction below the positive x-axis. You have a red ball with a mass of 3.6 kg moving with a speed of 2.7 m/s in a direction to the left of the negative y-axis. When the balls collide, find the final velocity (magnitude and direction) for each of the two balls.

Jennifer001

simple way to solve this is by using galilean transformation equations and turn one of the balls into a stationary one and just use the 1D formulas

asleight

Conservation of momentum holds in both the x- and y-directions.