a=/2+13-3/6, a=12/6, a=2.
b=/48+35+80/15, b=163/15,
c=/93-56-4/18, c=33/18, c=11/6.
a) 2+163/15+11/6=/60+326+55/30=441/30=147/10. e=147/10
b) 2-11/6+(1+163/15) =2-11/6+/15+163/15=2-11/6+178/15= /60-55+356/30=361/30, f=361/30.
c) 4/5+163/15+11/6-2= /24+326+55-60/30=345/30=23/2, g=23/2.