-1/2*3/5*(-2/7)
Just multiply numerators and denominators, then remove common factors:
(-1)(3)(-2)/(2)(5)(7)
not much to remove: just the 2 in top and bottom:
(-1)(3)(-1)/(5)(7) = 3/35
(-1)(3)(-2)/(2)(5)(7)
not much to remove: just the 2 in top and bottom:
(-1)(3)(-1)/(5)(7) = 3/35