Tìm số tự nhiên x,y biết : a.x(y +2 ) = 8 b.( x-2) ( 2y+3)=26 c.(x+5) (y-3)=15 d.xy+x+y = 2 mn giúp em với ,ai giải đc tất cả thì giải còn ai ko giải đc thì bao nhiêu cũng đc

1) Fe(NO3)3 + Fe -> Fe(NO3)2 2) Cu+ HNO3 -> Cu(NO3)2+ NO2 + H20 3) P + HNO3 -> H5PO4 Các bạn đặt ẩn rồi trình bày rõ ràng giúp mình nhé!

Giúp mình với ạ. Mình cảm ơn nhiều nhiều.

Tỉ lệ vs 4,5,6 nhé Nhanh nka mik cần gấp

cos^6x-sin^6x=13/8cos^2(2x) gấp lắm nhanh hộ nhé

Read the following story and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions Ha Long Bay is a UNESCO world Heritage site in Quang Ninh province, in the northeast of Viet Nam. It has got over 1,600 islands and islets. Among the many ancient fishing villages in ha Long, only Cua Van floating village remains. All the houses and the buildings in the village float on huge wooden rafts. The villagers spend their days fishing and looking after the sea life. Then they sail to the mainland to trade their fish to things like food, drinking water and clothes. Most children go to floating schools and then spend the rest of their time learning important skills like swimming and fishing. They also help out their parents as much as they can. Their lifestyles may seem strange to many people, but it’s wonderful to live among such natural beauty and know you are protecting it. The villagers are able to help preserve their beautiful bay because they live directly on the water. Question 24: The word “they” in paragraph 2 is closest in meaning to _________. A. the builders B. the schools C. the villagers D. the houses Question 25: According to the passage, the villagers’ lifestyles may seem ________to many people. A. tiring B. strange C. dangerous D. boring Question 26: The villagers not only fish but also _________ the sea life. A. pollute B. damage C. look at D. look after Question 27: The villagers are able to help preserve their beauty bay because _______. A. they live on the land B. they live far from the sea C. they don’t live directly on the water D. they live directly on the water

Nhờ mọi người giúp e với ạ!!!! E cảm ơn !!!

phân tích đa thức thành nhân tử=pp đổi biến a,<12x-1><6x-1><4x-1><2x-1>+4x^2 help meeeeeeeeeeeeeeeeeeeeeeeeeeee

Em đang cần gấp ạ anh chị giúp e với ạ.e cảm ơn anh chị

Phân tích các đa thức sau thành nhân tử : (a + b + c) ³ - 4(a ³ + b ³ + c ³) - 12abc bằng cách đổi biến : đặt a + b = m , a - b = n