Câu 1: Tính
4) 5 . [ ( 85 - 35 : (-7) + 90 ] + 491
Thực hiện phép tính : 5 [ ( 85 - 35: 7 ) : 80 + 90 ] - 50
5 . [(85 - 35 : 7) : 80 + 90] - 50
= 5 . [(85 - 5) : 80 + 90] - 50
= 5 . [80 : 80 +90] - 50
= 5 . [1 + 90] - 50
= 5 . 91 - 50
= 455 - 50 = 405
5 [ ( 85 - 35 : 7 ) : 80 + 90 ] - 50
= 5 [ ( 85 - 5 ) : 80 + 90 ] - 50
= 5 [ 80 : 80 + 90 ] - 50
= 5 [ 1 + 90 ] - 50
= 5 . 91 - 50
= 455 - 50
= 405
=))
5 x [ ( 85 - 35 : 7 ) : 8 + 90 ] -50
5 x [(85 - 35 : 7) : 8 + 90] - 50
= 5 x [(85 - 5) : 8 + 90] - 50
= 5 x [80 : 8 + 90] - 50
= 5 x [10 + 90] - 50
= 5 x 100 - 50
= 500 - 50
= 450
\(5\times\left[\left(85-35:7\right):8+90\right]-50\\ =5\times\left[\left(85-5\right):8+90\right]-50\\ =5\times\left[80:8+90\right]-50\\ =5\times\left[10+90\right]-50\\ =5\times100-50\\ =500-50=450\)
5 x [(85 - 35 : 7) : 8 + 90] - 50
= 5 x [(85 - 5) : 8 + 90] - 50
= 5 x [80 : 8 + 90] - 50
= 5 x [10 + 90] - 50
= 5 x 100 - 50
= 500 - 50
= 450
5 [( 85 - 35 :7) :8 +90] -50
help me
5[(85 - 35 : 7) : 8 + 90] - 50
= 5[(85 - 5) : 8 + 90] - 50
= 5.[ 80 : 8 + 90] - 50
= 5.[ 10 + 90 ] - 50
= 5. 100 - 50
= 500 - 50
= 450
5[(85 - 35 : 7) : 8 + 90] - 50
= 5[(85 - 5) : 8 + 90] - 50
= 5.[ 80 : 8 + 90] - 50
= 5.[ 10 + 90 ] - 50
= 5. 100 - 50
= 500 - 50
= 450
Tính giá trị biếu thức
a) 23.15 -[115-(12-5)2 ]
b)5.[(85 - 35 : 7) :8 + 90 ] - 50
c){[261 - ( 36-31)3.2 ]-9}.1001
d)3.102 - [1200 - ( 42 - 2.3)3]
\(a)2^3\cdot15-[115-(12-5)^2]\\=8\cdot15-(115-7^2)\\=120-(115-49)\\=120-66\\=54\\---\\b)5\cdot[(85-35:7):8+90]-60\\=5\cdot[(85-5):8+90]-60\\=5\cdot(80:8+90)-60\\=5\cdot(10+90)-60\\=5\cdot100-60\\=500-60\\=440\)
\(---\)
\(c,\left\{\left[261-\left(36-31\right)^3\cdot2\right]-9\right\}\cdot1001\)
\(=\left[\left(261-5^3\cdot2\right)-9\right]\cdot1001\)
\(=\left[\left(261-125\cdot2\right)-9\right]\cdot1001\)
\(=\left[\left(261-250\right)-9\right]\cdot1001\)
\(=\left(11-9\right)\cdot1001\)
\(=2\cdot1001\)
\(=2002\)
\(---\)
\(d,3\cdot10^2-\left[1200-\left(4^2-2\cdot3\right)^3\right]\)
\(=3\cdot100-\left[1200-\left(16-6\right)^3\right]\)
\(=300-\left(1200-10^3\right)\)
\(=300-\left(1200-1000\right)\)
\(=300-200\)
\(=100\)
#\(Toru\)
a) 23.15 -[115-(12-5)2 ]
= 23.15 -[115-36]
= 8.15 -79
= 120-79
=41
b)5.[(85 - 35 : 7) :8 + 90 ] - 50
=5 .[80:8+90]-50
=5.100-50
=500-50
=450
c){[261 - ( 36-31)3.2 ]-9}.1001
={[261 - 125.2 ]-9}.1001
={[261 -250 ]-9}.1001
={11-9}.1001
=2.1001
=2002
d)3.102 - [1200 - ( 42 - 2.3)3]
=3.100-[1200 -(16-6)3 ]
=300-[1200-1000]
=300-200
=100
85+(-35)+(-12)+(-35)
5 mũ 3 . 4 mũ 2 + 85. 5 mũ 3 - 5 mũ 7 : 5 mũ 4
85+(-35)+(-12)+(-35)=50+(-12)+(-35)=38+(-35)=3
53.42+85.53-57:54=125.16+85.125-53=125.16+85.125-125
=125.16+85.125-125.1=(16+85-1).125=100.125=12500
\(5\left[\left(85-35:7\right):8+90\right]-50\)
\(5.\left[\left(85-35:7\right):8+90\right]\)
\(=5.\left[\left(85-5\right):8+90\right]\)
\(=5.\left(80:8+90\right)\)
\(=5.\left(10+90\right)\)
\(=5.100\)
\(=500\)
\(5\left[\left(85-35:7\right):8+90\right]\)
\(=5\left[\left(85-5\right):8=90\right]-50\)
\(=5\left[80:8+90\right]-50\)
\(=5\left[10+90\right]-50\)
\(=5.100-50\)
\(=450\)
=5[(85 - 5)] : 8 + 90] - 50
=5[80 : 8 + 90] - 50
=5[10 + 90] - 50
=5 x 100 - 50
=500 - 50
=450
Mong các bn ủng hộ mk
2 mũ 3 - 5 mũ 3 : 5 mũ 2 + 12 . 2 mũ 2
5 . [ { 85 - 35 : 7 } : 8 + 90 ] - 5 mũ 2 . 2
\(2^3-5^3:5^2+12\cdot2^2=8-5+48=51\\ 5\left[\left(85-35:7\right):8+90\right]-5\cdot2^2\\ =5\left(80:8+90\right)-20=5\cdot100-20=480\)
a) 23 – 53 : 52 + 12.22 | b) 5[(85 – 35 : 7) : 8 + 90] – 50 |
c) 2.[(7 – 33 : 32) : 22 + 99] – 100 | d) 27 : 22 + 54 : 53 . 24 – 3.25 |
e) (35 . 37) : 310 + 5.24 – 73 : 7 | f) 32.[(52 – 3) : 11] – 24 + 2.103 |
g) (72005 + 72004) : 72004 | h) (57 + 75).(68 + 86).(24 – 42) |
i) (75 + 79).(54 + 56).(33.3 – 92) | j) [(52.23) – 72.2) : 2].6 – 7.25 |
a: \(2^3-5^3:5^2+12\cdot2^2\)
\(=8-5+48\)
\(=51\)
b: \(5\cdot\left[\left(85-35:7\right):8+90\right]-5\)
\(=5\cdot\left[10+90\right]-5\)
=495
Bài 1 : Tính nhanh
a) 212 + 109 + 188 b) 305 + 295 + 140 c) 9 . 4 . 25 . 8 . 125
d) 35 + 56 + 65 + 44 e)277 + 194 + 206 + 123 g) 8 . 25 . 2 . 4 . 5 . 125
h) 29 . 25 + 29 . 45 + 29 . 30 i) 36 . ( 143 + 57 ) + 64 . ( 143 + 57 )
k) 491 . ( 747 + 53 ) + 491 . ( 153 + 47)
Bài 2 :Phaỉ dùng bao nhiêu chữ số để viết các số
a) từ 1 đến 99 b) từ 100 đến 999 c) từ 1000 đến 9999
Bài 4 : Tính tổng
a) M = 1 + 2 + 3 +... + 103 b) N = 3 + 7 + 11 +...+ 99 c) C = 1+ 11 + 21 + ... + 991