Bài 1 :
e) $10^{2}$ - [60 : ($5^{6}$ : $5^{4}$ - 3 . 5)
= 100 - [60 : ($5^{2}$ - 3 . 5)
= 100 - [60 : (25 - 3 .5)
= 100 - [60 : (25 - 15)
= 100 - [60 : 10]
= 100 - 6
= 94
d) 2010 - 2000 : [486 - 2 × ($7^{2}$ - 6)]
= 2010 - 2000 : [486 -2 ×(49 - 6)]
= 2010 - 2000 : [486 - 2 × 43]
= 2010 - 2000 : [486 - 86]
= 2010 - 2000 : 400
= 2010 - 5
= 2005
đ) 8697 - [$3^{7}$ : $3^{5}$ + 2 × (13 - 3)]
= 8697 - [$3^{2}$ + 2 × (13 - 3)]
= 8697 - [9 + 2 × (13 - 3)]
= 8697 - [9 + 2 × 10]
= 8697 - [9 + 20]
= 8697 - 29
= 8668
Bài 2 :
a) 25 . 7 . 5 . 4 . 2
= 25 . 7 . (5 . 4) . 2
= 25 . 7 . 20 . 2
= 175 . 40
= 7000
b) 25 × 124 - 24 × 25 - 112
= 25 × (124 - 24) - 112
= 25 × 100 - 112
= 2500 - 112
= 2388
c) 21 . 16 + 37 . 21 + 21 . 63
= 21 . (16 + 37 + 63)
= 21 . 116
= 2436
d) 35 . 48 + 65 . 68 + 20 . 35
= 35 . (48 + 20) + 65 . 68
= 35 . 68 + 65 . 68
= 68 . (35 + 65)
= 68 . 100
= 6800
@Đậu Đậu
