Question

- 3.9 + (1.2) + (- 6.1) + (+2.8)=?
3) - 7/12 + (+1/8) + (-5/12) + (+3/4)=?

Answer 1

1) $-3,9+1,2-6,1+2,8=(-3,9-6,1)+(1,2+2,8)=-10+4=-6$
2) $-frac{7}{12}+ frac{1}{8}- frac{5}{12}+ frac{3}{4}=(-frac{7}{12}- frac{5}{12})+(frac{1}{8} + frac{3}{4})=-1+( (frac{1}{8} + frac{6}{8})=-1+ frac{7}{8}$$=- frac{1}{8}$