82 + 8 = ???
28 + 2 = ???
55 + 5 = ???
(-28) + ( -35 ) - 92 + ( - 82 )
15 - ( - 38 ) + ( -55 ) - 47
10-[ (82-48).5+(23.10+8):28]
\(10-\left[\left(8^2-48\right)\cdot5+\left(23\cdot10+8\right):28\right]\)
\(=10-\left[\left(64-48\right)\cdot5+\left(230+8\right):28\right]\)
\(=10-\left(16\cdot5+238:28\right)\)
\(=10-\left(80+\dfrac{17}{2}\right)\)
\(=10-80-\dfrac{17}{2}\)
\(=-17-\dfrac{17}{2}\)
\(=-17-8,5\)
\(=-25,5\)
Bỏ dấu ngoặc rồi tính các tổng sau
a) (−28)+(−35)−92+(−82) b) 15−(−38)+(−55)−47
a) (-28) + (-35) – 92 + (-82) = -28 – 35 – 92 – 82
= - (28 + 35 + 92 + 82) = - [(28 + 82) + (35 + 92)]
= - (110 + 127) = - 237.
b) 15 – (-38) + (-55) – (+47) = 15 + 38 – 55 – 47
= 53 – 55 – 47 = - (55 – 53) – 47= - 2 – 47 = - (2 + 47) = - 49
a) (-28) + (-35) – 92 + (-82) = -28 – 35 – 92 – 82
= - (28 + 35 + 92 + 82) = - [(28 + 82) + (35 + 92)]
= - (110 + 127) = - 237.
b) 15 – (-38) + (-55) – (+47) = 15 + 38 – 55 – 47
= 53 – 55 – 47 = - (55 – 53) – 47
= - 2 – 47 = - (2 + 47) = - 49
Tính nhanh:
1) 69.(− 74)−31.74
2) (− 2020).35− 2020.65
3) − 23.59 −159.23
4) −147.47+ (− 47).(− 47)−300
5) (− 72).30 −31.−30 + 3.+ 30
6) (−82).(−55)+ (−82)+ (− 46).(−82)
7) (− 41).135+135.(− 24)−35.(−65)
8) 125.( 2) .( 25).9.( 10) .4 3 0 − − −
9) ( 2) .( 25).( 125).( 2) .2.( 50) 2 3 − − + − −
10) 125.(−88)
1, 69. (-74) - 31 . 74
= (-69) . 74 - 31 . 74
= 74(-69 - 31)
= 74(-100)
= -7400
2, (-2020) . 35 - 2020 . 65
= 2020 . (-35) - 2020 . 65
= 2020(-35 - 65)
= 2020(-100)
= -202000
3, -23 . 59 - 159 . 23
= 23 . (-59) - 159 . 23
= 23(-59 - 159)
= 23 . (-218)
= -5014
4, -147 . 47 + (-47)(-47) - 300
= -147 . 47 + 47 . 47 - 300
= 47(-147 + 47) - 300
= 47 . (-100) - 300
= -4700 - 300
= -5000
5, (-72) . 30 - 31 . (-30) + 3 + 30
= (-72) . 30 + 31 . 30 + 3 + 30
= 30(-72 + 31 + 1) + 3
= 30 . (-40) + 3
= -1200 + 3
= -1197
6, (-82)(-55) + (-82) + (-46)(-82)
= (-82)(-55 + 1 - 46)
= (-82)(-100)
= 8200
7, (-41) . 135 + 135 . (-24) - 35 . (-65)
= 135(-41 - 24) - 35(-65)
= 135(-65) - 35(-65)
= (-65)(135 - 35)
= -65(100)
= -6500
10, 125 . (-88)
= 1000 . \(\frac{1}{8}\) . (-88)
= 1000 . (-11)
= -11000
Câu 8 với 9 mình ko hiểu nên ko giúp bn được
Chúc bạn học tốt!
Tính hợp lý nếu có thể
10 – [(82 – 48).5 + (23 .10 + 8)] : 28 - 70
\(=10-\left[16\cdot5+88\right]:28-1=9-8=1\)
=10-[(64-48).5+(8.10+8)]:28-1
=10-[80+88]:28-1
=10-168:28-1
=10-6-1
=3
Bài 1: Bỏ dấu ngoặc rồi tính các tổng sau:
a) (-28)+(-35)-92+(-82)
b) 15-(-38)+(-55)-47
107 – {38 + [7.32 – 24 : 6+(9 – 7)3]}:15
17) 10 – [(82 – 48).5 + (23.10 + 8)] : 28 - 70
\(107-\left\{38+\left[7.3^2-24:6+\left(9-7\right)^3\right]\right\}:15\)
\(=107-\left\{38+\left[7.3^2-24:6+2^3\right]\right\}:15\)
\(=107-\left\{38+\left[7.3^2-4+2^3\right]\right\}:15\)
\(=107-\left\{38+\left[63-4+2^3\right]\right\}:15\)
\(=107-\left\{38+\left[59+2^3\right]\right\}:15\)
\(=107-\left\{38+67\right\}:15\)
\(=107-105:15\)
\(=107-7\)
\(=100\)
107 – {38 + [7.32 – 24 : 6+(9 – 7)3]}:15
= 107 - {38+ [7.32 - 24 : 6 + 23 ]} : 15
= 107 - {38 + [ 7.9 - 24 : 6 + 8]} :15
= 107 - {38+[ 63 - 4 + 8]} : 15
= 107 - {38 + 67} : 15
= 107 - 105 : 15
= 107 - 7
= 100
17) 10 – [(82 – 48).5 + (23.10 + 8)] : 28 - 70
= 10 - [(64 - 48).5 + (8.10 +8)] : 28 - 70
= 10 - [16.5 + 88] : 28 - 70
= 10 - [80 + 88] : 28 - 70
= 10 - 168 : 28 - 70
= 10 - 6 - 1
= 3
nếu sai câu nào mong bạn thông cảm ^^
107 – {38 + [7.32 – 24 : 6+(9 – 7)3]}:15
= 107 - {38+ [7.32 - 24 : 6 + 23 ]} : 15
= 107 - {38 + [ 7.9 - 24 : 6 + 8]} :15
= 107 - {38+[ 63 - 4 + 8]} : 15
= 107 - {38 + 67} : 15
= 107 - 105 : 15
= 107 - 7
= 100
17) 10 – [(82 – 48).5 + (23.10 + 8)] : 28 - 70
= 10 - [(64 - 48).5 + (8.10 +8)] : 28 - 70
= 10 - [16.5 + 88] : 28 - 70
= 10 - [80 + 88] : 28 - 70
= 10 - 168 : 28 - 70
= 10 - 6 - 1
= 3
Tìm x , biết
a.128 - 3 ×( x +2 ) =23
b. ( 12 × x -64 ) × 8 = 4,64
c. [( 4 × x +28) × 3 + 55 ] : 5 = 35
d. 720 : [ 41 - ( 2 × x - 5 )] = 8 × 5
a. 128 - 3 x (X + 2) = 23
3 x (X + 2) = 128 - 23
X + 2 = 105 : 3
X = 35 - 2
X = 33
b. (12 x X - 64) x 8 = 4,64
12 x X - 64 = 4,64 : 8
12 x X = 0,58 + 64
X = 64,58 : 12
X = \(\frac{3229}{600}\)
c. [(4 x X + 28) x 3 + 55] : 5 = 35
[(4 x X + 28) x 3 + 55] = 35 x 5
(4 x X + 28) x 3 = 175 - 55
4 x X + 28 = 120 : 3
4 x X = 40 - 28
X = 12 : 4
X = 3
d. 720 : [41 - (2 x X - 5)] = 8 x 5
41 - (2 x X - 5) = 720 : (8 x 5)
2 x X - 5 = 41 - 18
2 x X = 23 + 5
X = 28 : 2
X = 14
x nhỏ : dấu nhân
X lớn : X