38 : 0,5 + 38 : 0,2 + 38 + 38 : 0,2
Những câu hỏi liên quan
a) x : 0,5 + x : 0,2 + x : 0,25 + x : 0,125 + x 38.................................................................................................................................................................................................................................................................................................................................................................................................................................................................
Đọc tiếp
a) x : 0,5 + x : 0,2 + x : 0,25 + x : 0,125 + x = 38
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b) (x + 2) + (x + 4) +….(x +18) + (x + 20) = 135
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A. 38 x 0,5 : 0,25
76 : 0,2 x 0,4
B. 98 x 0,2 : 0,5
49 x 0,2 : 0,5
Các bạn giải ra giúp mình nha
tìm y
120 + 8 x 20 = y + 25 x 10/ 4 - 0,5
100 - y + 0,5 x 2/2 =0
giúp tớ ạ
yêu mọi người ạ
Người ta dẫn 0,2 Kg hơi nước ở nhiệt độ 1000C vào một bình chứa 1,5 Kg nước đang ở nhiệt độ 150C. Tính nhiệt độ cuối cùng của hỗn hợp và tổng khối lượng khi xảy ra cân bằng nhiệt ?
Xem chi tiết
Nhiệt lượng tỏa ra khi 0,2 Kg hơi nước ở 1000C ngưng tụ thành nước ở 1000C
Q1 = m1. L = 0,2 . 2,3.106 = 460000 (J)
Nhiệt lượng tỏa ra khi 0,2Kg nước ở 1000C thành nước ở t0C
Q2 = m1.C. (t1 - t) = 0,2. 4200 (100 - t)
Nhiệt lượng thu vào khi 1,5Kg nước ở 150C thành nước ở t0C
Q3 = m2.C. (t - t2) = 1,5. 4200 (t - 15)
Áp dụng phương trình cân bằng nhiệt:
Q1 + Q2 = Q3
<=>460000 + 0,2. 4200 (100 - t) = 1,5. 4200 (t - 15)
<=>6780t = 638500
<=>t ≈ 940C
Tổng khối lượng khi xảy ra cân bằng nhiệt.
m = m1 + m2 = 0,2 + 1,5 = 1,7(Kg)
0,5% được viết thành phân số thập phân là
0,5%=50/100 nha
HT
Xem thêm câu trả lời
Bài 1, tính
a) 7/12+5/12:(-5/18)+(-2/3) mũ 2
b)(3/5+2/7):[4 là phần nguyên 3/7-(25/14.8/15-20/21)
c)9/10:1 phần nguyên 4/5-(-0,5) mũ 2-|1/2-1| mũ 3
GIẢI THÍCH CÁC BƯỚC GIẢI NHA
So sánh
A) -1/ 5 và -0,2
B) -2/ 3 và 4/ 9
C) -13/ 38 và 29/ -88
a) -1/5 = -0,2
b) -2/3 < 4/9
c) -13/38 > 2/-88
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Xem thêm câu trả lời
Cho m gam bột Mg vào dung dịch chứa 0,3 mol AgNO3 và 0,2 mol Fe(NO3)3, sau phản ứng thu được 38 gam chất rắn. Giá trị của m là:
A. 8,4 gam
B. 9,6 gam
C. 7,2 gam
D. 6,0 gam
20 tháng 5 2021 lúc 16:03
43. How have you been getting on with your enquiries?- How much …………………………………………………………44. I gave Ted the massage, but he already knew about it- I needn’t …………………………………………………………45. The trains couldn’t run because of the snow- The snow …………………………………………………………46. I didn’t arrived in time to see him- I wasn’t …………………………………………………………47. I’m sorry I was rude to you yesterday- I apologize …………………………………………………………48. She didn’t hurry, so she missed the train- If .…………………………………………………………49. Barbara is the bes...
Đọc tiếp
43. How have you been getting on with your enquiries?
-> How much …………………………………………………………
44. I gave Ted the massage, but he already knew about it
-> I needn’t …………………………………………………………
45. The trains couldn’t run because of the snow
-> The snow …………………………………………………………
46. I didn’t arrived in time to see him
-> I wasn’t …………………………………………………………
47. I’m sorry I was rude to you yesterday
-> I apologize …………………………………………………………
48. She didn’t hurry, so she missed the train
-> If .…………………………………………………………
49. Barbara is the best tennis – player in the club
-> No one …………………………………………………………
50. I haven’t seen that man here before
-> It’s …………………………………………………………
51. The furniture was so expensive that I didn’t buy it
-> The furniture was …………………………………………………………
52. The robbers made the bank manager hand over on the money
-> The bank manager …………………………………………………………
53. Tom learned to drive when he was nineteen
-> Tom has …………………………………………………………
54. She had never been so unhappy before
43. How have you been getting on with your enquiries?
-> How much progress have you been making with your enquiries?
44. I gave Ted the massage, but he already knew about it
-> I needn’t have given Ted the message because he already knew about it
45. The trains couldn’t run because of the snow
-> The snow prevented the trains from running
46. I didn’t arrived in time to see him
-> I wasn’t early enough to see him
47. I’m sorry I was rude to you yesterday
-> I apologize for being rude to you yesterday
48. She didn’t hurry, so she missed the train
-> If she had hurried , she wouldn't have missed the train
49. Barbara is the best tennis – player in the club
-> No one in the club plays tennis better than Barbara
50. I haven’t seen that man here before
-> It’s the first time I have ever seen that man
51. The furniture was so expensive that I didn’t buy it
-> The furniture was too expensive for me to buy
52. The robbers made the bank manager hand over on the money
-> The bank manager was made hand over on the money by the robbers
53. Tom learned to drive when he was nineteen
-> Tom has learnt to drive since he was nineteen
54. She had never been so unhappy before
=> She was unhappier than ever before ( câu này tk)
43. How much progress have you made with your enquiries?
44. I needn’t have given Ted the massage, because he already knew about it.
45. The sow prevented the trains from running.
46. I wasn’t early enough to see him.
47. I apologize for being rude to you yesterday.
48. If she had hurried, she would have caught the train
49. No one in the club is better at tennis than B.
50. It’s the first time I have seen that man.
51.The furniture was too expensive for me to buy.
52.The bank manager was made to hand over the money.
53. Tom has been able to drive since he was nineteen.
54. She was unhappier than she had ever before.