递等式计算:78×56+27×78+13×83+83×9934+9934+99934+999934150+250+350+…+4950.-数学
题文
递等式计算: 78×56+27×78+13×83+83×9 9
|
答案
(1)78×56+27×78+13×83+83×9, =78×(56+27)+83×(13+9), =78×83+83×22, =(78+22)×83, =100×83, =8300; (2)9
=9+
=(9+99+999+9999)+(
=(10+100+1000+10000-4)+(
=(11110-4)+3, =11106+3, =11109; (3)
=
=
=
|