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\(\frac{7}{2}\div\left(2,5-\frac{15}{4}\right)+\left(\frac{-1}{2}\right)^2\)
\(=\frac{7}{2}\div\left(\frac{5}{2}-\frac{15}{4}\right)+\frac{1}{4}\)
\(=\frac{7}{2}\div\left(\frac{10}{4}-\frac{15}{4}\right)+\frac{1}{4}\)
\(=\frac{7}{2}\div\frac{-5}{4}+\frac{1}{4}\)
\(=\frac{-14}{5}+\frac{1}{4}\)
\(=-\frac{56}{20}+\frac{5}{20}\)
\(=-\frac{51}{20}\)
~Study well~
#Zu
a) 32 . 53 + 92 = 9 . 125 + 81
= 1 125 + 81 = 1 206
b) 83 : 42 - 52 = 512 : 16 - 25 = 32 - 25 = 7
c) 33 . 92 - 52.9 + 18 : 6 = 27 . 81 - 25 . 9 + 3
= 2 187 - 225 + 3 = 1 962 + 3 = 1 965
a)[545-(45+4.25:50-2000:250+215:213
Đề bài sai
c) 5.{26-[3.(5+2.5)+15]:15}>
= 5.(26-(3.( 3.5 )+15):15)
= 5.(26-(3. 15 +15): 15)
= 5.(26-(3. 2. (15: 15)))
= 5.(26-(3. 2. 1 ))
= 5.(26- 6 )
= 5. 20
= 100 (máy tính của mik nó bị lỗi dấu ngoăc nhọn và ngoac vuông,mong bạn thông cảm)
a)[545-(45+4.25:50-2000:250+2\(^{15}\):2\(^{13}\) )
= [545- ( 45 + 100 : 50 - 2000 + \(2^2\))
= [545- ( 45 + 2 - 2000 + 4 )
= [ 545 - ( 47 - 2000 + 4 )
= [ 545 - ( -1935 + 4 )
= 545 - - 1949
= 2994
c) 5.{26-[3.(5+2.5)+15]:15}
5 . { 26 - [ 3 . ( 5 + 10 ) + 15 ] : 15 }
= 5 . { 26 - [ 3 . 15 + 15 ] : 15 }
= 5 . { 26 - [ 45 + 15 ] : 15 }
= 5 . { 26 - 60 : 15 }
= 5 . { -34 : 15 ]
= 5 . \(\frac{-34}{15}\)
= \(\frac{-34}{3}\)
Ta có : \(\frac{5^4+2^2.5^2-125}{2^2.3}=\frac{5^4+5^2.2^2-5^3}{8.3}=\frac{5^2\left(5^2+2^2-5\right)}{24}=\frac{5^2.24}{24}=5^2=25\)
Bài 1 :
a) 1440 : [ 41 - (2x - 5)] = 24.3
=> 1440 : [41 - (2x - 5)] = 16.3
=> 1440 : [41 - (2x - 5)] = 48
=> 41 - (2x - 5) = 1440 : 48 = 30
=> 2x - 5 = 11
=> 2x = 16
=> x = 8
b) 5 . [225 - (x - 10)] - 125 = 0
=> 5 . [225 - (x - 10)] = 125
=> 225 - (x - 10) = 125 : 5
=> 225 - (x - 10) = 25
=> x - 10 = 200
=> x = 210
Bài 2 :
a) [ 545 - (45 + 4.25)] : 50 - 200 : 250 + 215 : 213
= [ 545 - (45 + 100)] : 50 - 4/5 + 22
= [545 - 145] : 50 - 4/5 + 4
= 400 : 50 - 4/5 + 4 = 8 - 4/5 + 4 =56/5
Mấy câu còn lại tương tự
Bài 1.
a, 1440:[41-(2x-5)]=24.3
1440:[41-(2x-5)]= 16.3
1440:[41-(2x-5)]=48
[41-(2x-5)] =1440:48
[41-(2x-5)] = 30
2x-5 = 41-30
2x-5 =11
2x = 11+5
2x = 16
x = 16:2
x =8
b, 5.[225-(x-10)]-125=0
5.[225-(x-10)] =125
[225-(x-10)] =125:5
[225-(x-10)] = 25
(x-10) = 225-25
(x-10) = 200
x =200+10
x = 210
Bài 2.
a, [545-(45+4.25)]:50-200:250+215:213
= [545-(45+100)]:50-200:250+22
= [545-145]:50- 200:250+4
= 400:50-200:250+4
= 8-0,8+4
= 7,2 + 4
= 11,4
b, [504-(25.8+70)]:9-15+190
= [504-(200+70)]:9-15+1
= [504-270]:9-16
= 234:9-16
= 26-16
= 10
c, 5.{26-[3.(5+2.5)+15]:15}
= 5.{26-[3.(5+10)+15]:15}
= 5.{26-[3.15+15]:15}
= 5.{26-[45+15]:15}
= 5.{26-60:15}
= 5.{26-4}
=5.22
= 110
d,[1104-(25.8+40)]:9+316:312
= [1104-(200+40)]:9+34
=[1104-240]:9+34
=864:9+81
=96+81
=177
hok tốt
Số số hạng cua dãy là:
(200-1):1+1=200(số hạng)
Giá trị của dãy số là:
(200*201):2=20100
1 + 2 + 3 + 4 + ... + 200 = ( 200 + 1 ) . 200 : 2 = 201 . 200 : 2 = 20100
\(\frac{9}{2}:\left(2.5-\frac{15}{4}\right)+\left(\frac{-1}{2}\right)^2\)
\(=\frac{9}{2}:\left(10-\frac{15}{4}\right)+\frac{1}{4}\)
\(=\frac{9}{2}:\left(\frac{40}{4}-\frac{15}{4}\right)+\frac{1}{4}\)
\(=\frac{9}{2}:\frac{25}{4}+\frac{1}{4}\)
\(=\frac{9}{2}.\frac{4}{25}+\frac{1}{4}\)
\(=\frac{18}{25}+\frac{1}{4}\)
\(=\frac{97}{100}\)
\(\frac{9}{2}\div\left(2\times5-\frac{15}{4}\right)+\left(\frac{-1}{2}\right)^2\)
\(=\frac{9}{2}\div\left(10-\frac{15}{4}\right)+\left(\frac{-1}{2}\right)^2\)
\(=\frac{9}{2}\div\left(\frac{40-15}{4}\right)+\frac{1}{4}\)
\(=\frac{9}{2}\div\frac{25}{4}+\frac{1}{4}\)
\(=\frac{9}{2}\times\frac{4}{25}+\frac{1}{4}\)
\(=\frac{18}{25}+\frac{1}{4}\)
\(=\frac{72+25}{100}=\frac{97}{100}\)