Hi,

I'm trying to find the closed form of a second-order sequence. I'm down to the 'general solution' which is ( Un = A6/5^n + B(-2)^n ), but I'm having a simultaneous equation mind block.

Here's where I'm stuck:

U0 = 2 gives A + B = 2

U1 = 12 gives 6/5A - 2B = 12

Please can someone help to jog my memory on simultaneous equations, I'm staring blankly at these and Mathcad isn't helping.

Thanks.