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28 tháng 11 2021
a) 1024 : 25 + 140 : ( 38 + 25 ) - 723 : 721
= 1024 : 32 + 140 : ( 38 + 32 ) - 72
= 32 + 140 : 70 - 49
= 32 + 2 - 49
= 34 - 49
= -15
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2 tháng 12 2021
Gọi x là số học sinh khi giả sử: x ⁝ 2, 3, 4, 5, 6, chúng ta đã có thêm 1 học sinh; gọi a là số học sinh trong thực tế.
x ⁝ 2
x ⁝ 3
x ⁝ 4
x ⁝ 5
x ⁝ 6
⇒ x ∈ BC( 2, 3, 4, 5, 6 )
⇒ x = 60
x ∈ { 60, 120, 180, 240, 300, 360... }
a ∈ { 59, 119, 179, 239 }
a ∈ 119 vì chỉ có 119 chia hết cho 7.
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A
0
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Câu 1
a,\(\dfrac{-6}{15}\)+ \(\dfrac{20}{15}\)=\(\dfrac{14}{15}\)
b,\(-\dfrac{5}{4}\) +\(\dfrac{36}{48}\)=\(-\dfrac{5}{4}\) +\(\dfrac{3}{4}\)=\(\dfrac{-1}{2}\)
c,\(\dfrac{-15}{17}\)x\(\left(\dfrac{13}{20}+\dfrac{7}{20}\right)\) =\(\dfrac{-15}{17}\)x1=\(\dfrac{-15}{17}\)
Bài 1
a) -2/5 + 4/3 = -6/15 + 20/15 = 14/15
b) -5/4+ 4/6. 9/8 =-14/24 . 9/8 = -7/3 . 1/4 = -7/12
c) -15/17 . 13/20 + -15/17 . 7/20 = -15/17 [ 13/20 + 7/20 ]
= -15/17 . 20/20 = -15/17 . 1
= -15/17
Bài 2
Tỉ số của số tiền khi mai mua bút và vở là :
1/3 + 2/5 = 11/15 {tổng số tiền}
Tỉ số của số tiền khi mai mua thước là :
1 - 11/15 = 4/15 { tổng số tiền}
Số tiền để mai mua thước kẻ là :
45.[4/15] = 12 nghàn đồng
Đ/S:..
Bài 3
AB = BO - OA = 7 - 3 = 4cm
OM =OA + AM = 3 + { 4:2 } = 3+2 = 5 cm![](data:image/png;base64,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)
Bài 4
M = 1/1.7 + 1/7.13 + 1/13.19 + ...... + 1/ 33.39
6M = 1/1 - 1/7 + 1/7 - 1/ 13 + .... + 1/33 - 1/39
6M = 1 - 1/39 = 38/39
M = 38/39 : 6 = 38/234 = 19/117 tick nếu đúng :v