<span>let:
m1 = 2xy a
m2 = 2xy b
m3 = 2x2y c
since 2 and 3 have a common factor let b=2n
m1 = 2xy a
m2 = 2xy 2 n
m3 = 2x2y c
or simply
m1 = 2xy a
m2 = 2xy 2n
m3 = 2xy 2c
given that anc have no common factors</span>
You can solve this by making a proportion.

you cross multiply and divide to solve this. your answer is 8.