简便计算(递等式)①11×11×11—11×11 ②1/2+1/6+1/12+1/20+1/30 ③48—(32÷3/8—5/12)④1/2-1/3+1/4-1/5+1/6-1/12

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简便计算(递等式)①11×11×11—11×11 ②1/2+1/6+1/12+1/20+1/30 ③48—(32÷3/8—5/12)④1/2-1/3+1/4-1/5+1/6-1/12
简便计算(递等式)①11×11×11—11×11 ②1/2+1/6+1/12+1/20+1/30 ③48—(32÷3/8—5/12)
④1/2-1/3+1/4-1/5+1/6-1/12

简便计算(递等式)①11×11×11—11×11 ②1/2+1/6+1/12+1/20+1/30 ③48—(32÷3/8—5/12)④1/2-1/3+1/4-1/5+1/6-1/12
①11×11×11—11×11
=11×11×(11—1)
=11×11×10
=1210
②1/2+1/6+1/12+1/20+1/30
=1/2×(1+1/3+1/6+1/10+1/15)
=1/2×(1+1/3+1/6+1/6)
=1/2×(1+1/3+1/3)
=1/2×(1+2/3)
=1/2×5/3
=5/6
③48—(32÷3/8—5/12)
=48-(32×8/3-5/12)

11×11×11—11×11
=11x11x11-11x11x1
=11x11x(11-1)
=121x10
=1210其他的呢?其他的能答出来设你为满意回答1/2+1/6+1/12+1/20+1/30 =3/6+1/6+1/12+1/20+1/30 =2/3+1/12+1/20+1/30 =8/12+1/12+1/20+1/30 =3/4+1/20...

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11×11×11—11×11
=11x11x11-11x11x1
=11x11x(11-1)
=121x10
=1210

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