a)
12-\frac{2}{7}-7+13\frac{3}{7}=12+13-7-\frac{2}{7}+\frac{3}{7}=25-7+\frac{1}{7}=18\frac{1}{7}
b)
-5,8+2,7+2,2+0,3=-5,8-2,2+2,7+0,3=-8+3=5
c)
-5\frac{1}{8}+1\frac{1}{12}+2\frac{7}{12}+\frac{1}{8}=1+2-5+\frac{1}{8}-\frac{1}{8}+\frac{1}{12}=3-5+0+\frac{1}{12}=-2+\frac{1}{12}=-1\frac{12}{12}+\frac{1}{12}=-1\frac{11}{12}
d)
-0,5-\frac{3}{4}+1\frac{1}{2}-0,25=-0,5-0,75+1,5-0,25=1,5-0,75-0,25-0,5=1,5-1-0,5=1,5-1,5=0