I don't think you are asking a math question, but in my opinion you should choose a leader that you think would be responsible in a group, then tell them what the group needs to do.
Must do multiplication first.... -2/5 - 3/7 x 7/10 -2/5 - 21/70 (I'll reduce 21/70) -2/5 - 3/10 Now you have to find a common denominator and subtract -35/50 = -7/10......is what I get
