chemistry
posted by lyne .
for my test i have to be able to
Be able to determine the final molarity of a mixture of two solutions
my teacher said the formula was m1v1 = m2v2/m1+v2 or something like that
is that right??

I have no idea with such a limited amount of information. But here is how you do it. It's much easier than memorizing a formula AND it contains the same information you have been using.
Just determine the moles of 1 of the solutions. That is M x L.
Then determine the moles of the other solution. That is M x L.
Then add the moles together to obtain the total moles in the final solution and divide by the total volume and you have it. 
thanks