17 / 77 * 10 + 17 / 77 * 9 + 17 / 77 * 8 + …… 17 / 77 * 1= 17 / 77 * (10 + 9 + 8 + 7 + 6 …… + 2 + 1)= 17 / 77 * (1 + 10)* 10 ÷ 2= 17 / 77 * 11 * 5= 17 ÷ 11 ÷ 7 * 11 * 5= 17 ÷ 7 * 5= 85 / 7
原式=17/77*(10+9+8+7+6..+2+1) =17/77*(10+1)*10*1/2 =17/77*55 =935/77
99x7+77x9+33x18=99*7+99*7+33*3*6=99*(7+7+6)=99*20=1980
557254
99*7+77*9+33*18 =99*(7+7+6) =99*20 =1980 你好,本题已解答,如果满意 请点右下角“采纳答案”.
=(10+9+8+7+……+1)*17/77=55*17/77=85/7
不知道,1000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
加到哪呀一吗(17/77)*(10+9+8+7+6+5+4+3+2+1)=(17*55)/77=85/7
17*10/77+17*9/77++17*2/77+17/77=(17/77)(10+9++2+1)=(17/77)*(10*11/2)=17*5*11/77=85/7
17/8*9/2+17/8*9/8=17/2*9/8+17/8*9/8=(17/2+17/8)*9/8=85/8*9/8=765/64