Tính bằng hằng đẳng thức a) (a+b+c)^2 = b) (a+b-c)^2=

Cho tam giác ABC, AH⊥BC.M là trung điểm của BC. Biết ∠BAH= ∠CAM a, Chứng Minh:HB/HC=AB²/AC² b,Chứng minh: AB=AC hoặc ∠BAC=90

giúp mình làm bài toán này với nha chữ hơi xấu xíu làm bài 1 tìm x nha

Cho A = x ³ + y ³ + z ³ - 3xyz a) Chứng minh rằng nếu x + y + z = 0 thì A bằng 0 b) Điều đảo lại có đúng không? Giúp mình với

Giải hộ mình mình đang cần gấp

1. Nam said: " I can sole that problem". 2. Dick said: " I must leave at eight". 3. Henry said: " I finish all of my homework in the afternoon" 4. "You must do it now" The teacher said to us. 5." These roses are cut from my garden" said my aunt. 6. "It is so foggy today," he said. 7. " I have to clean the floor today," he said 8. "Nothing can grow in my garden. It never gets any sun," she said. 9. He said," I have a toothache." 10. She said," I go to the museum every day." 11. He said, " I like this song." 12." I don't speak Italian," she said. 13." The film begin at seven o'clock," he said. 14. " I never make mistakes." he said. 15. " I am very tired," he said. 16. " I will get myself a drink," she said. 17. " I cannot drive them home," he said. 18. He said, " i dont's know what happens." 19. " I have already done my homework," he said. 20. She said, "I'll write him a prescription." 21. They said, " We're going to the drugstore." 22. He said" I don't like singing a lot." 23. She said, " I go to the supermarket every day." 24. "I have never spoken Italian before" she said. 25. They said, "We want to visit Cannery Row."

cos(3x−π/6)= 1 mình xin cảm ơn ạ ́

Bài 1 a, Tính $2^{2}$ . 3 - ( $1^{10}$ + 8 ) : 3 $6^{2}$ : 43 + 2 . $5^{2}$ $3^{3}$ . 118 - $3^{3}$.18 15. $2^{3}$ + 4.3 - 5.7 150 - [$10^{2}$ - (14 - $11)^{2}$ . $2007^{0}$ ] 4.$5^{2}$ -3 . $2^{3}$

giúp mình $\frac{x:2}{3}$ = $\frac{5}{15}$

Giải thích giúp ạ |5x+1|-10x=0,5