Đáp án:
Bài 1:
a) 5³ . 23 - 5³ . 18
= 125 . 23 - 125 . 18
= 125 . (23 - 18)
= 125 . 5
= 625
b) 200 : {250 : [450 - (4 . 5³ - 2² . 25)]}
= 200 : {250 : [450 - (4 . 125 - 4 . 25)]}
= 200 : {250 : [450 - (500 - 100)]}
= 200 : {250 : [450 - 400]}
= 200 : {250 : 50}
= 200 : 5
= 40
c) $(20 . 2^{4} + 12 . 2^{4} + 12 . 2^{4} - 48 . 2²) : 8²$
= (20 . 16 + 12 . 16 + 12 . 16 - 48 . 4) : 64
= [16 . (20 + 12 + 12) - 48 . 4) : 64
= [16 . 44 - 48 . 4] : 64
= [704 - 192] : 64
= 512 : 64
= 8
Bài 2:
a) 1027 - 4 . x = 175
4 . x = 1027 - 175
4 . x = 852
x = 852 : 4
Vậy x = 213
b) 720 : [41 . (2 . x - 5)] = 2³ . 5
720 : [41 . (2 . x - 5)] = 8 . 5
720 : [41 . (2 . x - 5)] = 40
[41 . (2 . x - 5)] = 720 : 40
41 . (2 . x - 5) = 18
2 . x - 5 = 18 : 41
2 . x - 5 = $\dfrac{18}{41}$
2 . x - 5 = $\dfrac{18}{41}$
2 . x = $\dfrac{18}{41}$ + 5
2 . x = $\dfrac{18}{41} + \dfrac{205}{41}$
2 . x = $\dfrac{223}{41}$
x = $\dfrac{223}{41}$ : 2
x = $\dfrac{223}{41} . \dfrac{1}{2}$
x = $\dfrac{223}{82}$
Vậy x = $2\dfrac{59}{82}$
@Yết gửi bạn nhé~~
HỌC TỐT~~
#NOCOPY
#NOTHINGISIMPOSSIBLE
