Overview: 2 questions will be solved this time.Among them
           ☆2 arithmetic calculations

[1/2 Formula]
    Work: Calculate the value of equation (1/3+1/5+1/7)*(1+1/3+1/5)-(1+1/3+1/5+1/7)*(1/3+1/5) .
    Question type: Mathematical calculation
    Solution:
          (1/3+1/5+1/7)*(1+1/3+1/5)-(1+1/3+1/5+1/7)*(1/3+1/5)
        =0.67619*(1+1/3+1/5)-(1+1/3+1/5+1/7)*(1/3+1/5)
        =0.67619*1.533333-(1+1/3+1/5+1/7)*(1/3+1/5)
        =0.67619*1.533333-1.67619*(1/3+1/5)
        =0.67619*1.533333-1.67619*0.533333
        =1.036824-1.67619*0.533333
        =1.036824-0.893967
        =0.142857
    Answer:(1/3+1/5+1/7)*(1+1/3+1/5)-(1+1/3+1/5+1/7)*(1/3+1/5)=0.142857
[2/2 Formula]
    Work: Calculate the value of equation 3+5+7+9+11+13+15+17 .
    Question type: Mathematical calculation
    Solution:
          3+5+7+9+11+13+15+17
        =8+7+9+11+13+15+17
        =15+9+11+13+15+17
        =24+11+13+15+17
        =35+13+15+17
        =48+15+17
        =63+17
        =80
    Answer:3+5+7+9+11+13+15+17=80

Your problem has not been solved here? Please go to the Hot Problems section！