2 1 5 m 2 5 ) 3 5 July 8, 2019 16 32 64 128 2 1 5 m 2 5 )+ 3 5 2 left ( dfrac 1 5 m - dfrac 2 5 right )+ dfrac 3 5 2 left ( frac 1 5 m - dfrac 2 5 right )+ frac 3 5 2 left ( dfrac 1 5 m - dfrac 2 5 right )+ dfrac 3 5 answer 3 5 m 2 5 2 m m 1 1 5 mm