Stuck on M1 Vector Question??

I'm really stuck on this question, don't even know where to start with it Please help!

"A particle starts from the point with position vector 4j m and moves with constant velocity (2i-j) ms^-1. At the same time a second particle starts from the point with position vector (6i+8j) m and moves with constant velocity (-i-3j) ms^-1. Show that the particles collide, and find the time at which they do so."

I feel like I need to make some simultaneous equations to find t, and I've drawn a diagram, but apart from that I'm not getting anywhere...

OK - hint - how far will the first particle go in t seconds? Then it's postition vector will be 4j plus this.

Post what you get