3,1*8,2+12,5*4,8+3,1*4,3-12,5*6,7

Question

3,1*8,2+12,5*4,8+3,1*4,3-12,5*6,7

Answer 1

3,1*8,2+12,5*4,8+3,1*4,3-12,5*6,7 =3.1*(8.2+4.3)+12.5*(4.8-6.7)=3.1*12.5+12.5*(-1.9)=12.5*(3.1-1.9)=12.5*1.2=15

Answer 2

3.1×8.2=25.42
12.5×4.8=60
3.1×4.3=13.33
12.5×6.7=83.75
24.42+60+13.33-83.75=15
3,1*8,2+12,5*4,8+3,1*4,3-12,5*6,7=15