Question

13 2/15c-15 1/3c+3,5c-4/5c

Answer 1

13 2/15 с - 15 1/3 с + 3,5с - 4/5 с = с * (13 2/15 - 15 1/3 + 3,5 - 4/5) =

= с * (13 2/15 - 15 5/15 + 3,5 - 12/15) = с * (197/15 - 230/15 + 3,5 - 12/15) =

= с * (-45/15 + 3,5) = с * (-3 + 3,5) = с * 0,5 = 0,5с   (или  1/2 с)