Giải thích các bước giải:
Vì x,y,z là số nguyên tố $\to x,y,z\ge 2$
$\to x^y\ge 2^2=4\to z-1\ge 4\to z\ge 5\to z$ lẻ
$\to x$ chẵn $\to x=2$
$\to 2^y=z-1$
$\to z=2^y+1$ là số nguyên tố
$+) y=2\to z=5\to (x,y,z)=(2,2,5)$
$+) y\ne 2\to y=2k+1$
$\to z=2^{2k+1}+1\equiv (-1)^{2k+1}+1\equiv 0(mod 3)$
$\to z\quad\vdots\quad 3\to z=3\to 2^y+1=3\to y=1$ Loại
Vậy $(x,y,z)=(2,2,5)$
Lại tặng đ cho mn đây ( x-2 ).(3+x)=2 . (x-2)
Câu 33. Tam giác ABC vuông tại B suy ra: A. AB2 = BC2 + AC2 B. BC2 = AB2 + AC2 C. AC2 = AB2 + BC2 D. Cả a,b,c đều đúng P/s: giúp mình câu này với ạ !!!!
Cho tứ giác ABCD có diện tích S. Gọi K, L, M, N lần lượt là các điểm thuộc các cạnh AB, BC, CD, DA sao cho A K/ A B = B L/ B C = C M/ C D = D N/ D A . Xác định vị trí các điểm K, L, M, N sao cho diện tích tứ giác KLMN nhỏ nhất. Giúp mk với
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Tiến hành nhiệt phân 100 gam CaCO3 , thu được 33 gam CO2 . Hiệu suất của phản ứng nhiệt phân là A: 75%. B: 42%. C: 33%. D: 67%.
Bất cứ ai giải xong bài này nhất định mình sẽ tặng 1 vote 5 sao kèm với một cảm ơn ( Toán 8 hình học bài tập định lý Talet và hệ quả)
Hợp chất hữu cơ nào sau đây không có khả năng tham gia phản ứng cộng ? A: Etilen. B: Metan. C: Axetilen. D: Benzen.
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31. The car was so expensive that I didn't buy it. A. The car was too expensive for me to buy. B. The car was such expensive that I didn't buy it. C. The car was not so cheap that I couldn’t buy it. D. The car was cheap enough for me to buy. 32. The coffee is so strong that I really can’t drink it. A. It is such coffee strong that I really can’t drink it. B. The coffee is too strong for me can’t drink it. C. It is such strong coffee that I really can’t drink it. D. The coffee is too strong for me to drink it. 33. It is such a bad book that nobody reads it. A. This book is too bad that nobody reads it. B. This book is too bad for nobody to read. C. This book is so bad that nobody reads it. D. This book is so bad for anybody to read it. 34. The room was too dark for us to see anything. A. The room was so dark that we couldn’t see anything. B. It was such a dark room that we couldn’t see anything. C. The room was very dark for us to see anything. D. A & B 35. It was such a crazy story that nobody believed it. A. The story was too crazy to believe it. B. The story was too crazy to believe. C. The story was so crazy that nobody believed. D. The story was too crazy nobody believe it. 36. She danced so well that she won the prize. A. She danced well enough to win the prize. B. She didn’t dance well enough to win the prize. C. She danced too well to win the prize. D. It was such a good girl that she won the prize. 37. This song is simple enough for us to sing. A. This song is so simple that we can sing. B. This song is so simple that we can sing it. C. This song is so simple for us to sing. D. It is such a simple song that we can sing. 38. The dress is not big enough for her to wear. A. It is such a small dress that she can’t wear it. B. The dress is so small that she can’t wear it. C. The dress is too small for her to wear. D. All are correct 39. The cake was too hard for him to eat. A. The cake was so hard that for him to eat. B. It was such hard cake that he could not eat. C. The cake was so hard that he couldn’t eat it. D. The cake was so hard that he can’t eat it. 40. The bag was too heavy for him to carry. A. The bag wasn’t enough light for him to carry. B. The bag was so heavy that he couldn’t carry. C. It was such a heavy bag for him to carry. D. It was such a heavy bag that he couldn’t carry it. 41. The garden is too small to play football in. A. The garden is so small not to play football in. B. The garden is small enough to play football in. C. The garden isn’t big enough to play football in. D. The garden is such small that they can’t play football in. 42. It was such bad coffee that he couldn’t drink it. A. The coffee was not good enough for him to drink. B. The coffee was so bad that he couldn’t drink it. C. The coffee was too bad for him to drink. D. All are correct 43. He isn’t strong enough to carry this table. A. He isn’t too weak to carry this table. B. He is too strong to carry this table. C. He is too weak to carry this table. D. He isn’t enough strong to carry this table
Tìm số tự nhiên x biết 3^7x-11 = 135 (7x-11 đều là mũ của 3 nhé mn) Giúp em đi ah !!!!!!!!!!!!!!! Hứa vote, cảm ơn đầy đủ ah
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