Đáp án+Giải thích các bước giải:
a,
$7x^2+14xy$$=7x(x+2y)$b,$x^2-2x-15$$=x^2-2x+1-16$$=(x-1)^2-16$$=(x-1-4)(x-1+4)$$=(x-5)(x+3)$
a) `7x^2+14xy`
`=7x(x+2y)`
b) `x^2-2x-15`
`=(x^2-5x)+(3x-15)`
`=x(x-5)+3(x-5)`
`=(x-5)(x+3)`
mọi người giải chi tiết từng bước giúp em ạ
Choose the best answer : 1. _______ we lived in town, we often went to the theater a. After b. When c. For d. Or 2. He took the food eagerly, _ he had eaten nothing since dawn.a. if b. in case c. but d. for 3. _______ the sun rose, the fog dispersed.a. As b. When c. Before d. After 4. _______ a married man, he has to think of his family. a. If b. As c. or d. so 5. Tired___ he was, he offered to carry her.a. as b. though c. Although d. however 6. Some people waste food_______ others don't have enough. a. as b. in case c. while d. before 10. Strong_______ he was, he couldn't lift it.a. like b. as c. or d. and 14. Take a map with you _______ you lose your way.a. if b. in case c. so that d. so 15. The play was very boring, _______ they walked out.a. so b. if c. when d. while 16. She'll only do the job_______ you pay he more.a. unless b. after c. if d. as 17. He hasn't written to us_______ he left.a. when b. for c. because d. since 18. I never take and umbrella_______ it's raining heavily.a. unless b. if c. otherwise d. or 19. He got a new alarm clock_______ he'd get up on time. a. because b. and c. so that d. so' 20. He agreed to go climbing_______ he hated heights. a. despite b. in spite of c. so d. although
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Thực hiện phép tính ạ Nhanh ạ Cần gấp
I wish my summer holiday .... longer A Will be B is C were D has been
Công thức rút gọn sinx+ cosx= √2 ...............= √2............... sinx- cosx= √2 ...............= √2...............
Tìm x 1. 4x ( x-3) - (2x-5)^2=-1
PK0020C - Tìm nghiệm Dữ liệu vào: standard input Dữ liệu ra: standard output Giới hạn thời gian: 1.0 giây Giới hạn bộ nhớ: 128 megabyte Đăng bởi: A2K53PK Xét một phương trình có dạng như sau: x + y + z = n ( n là một số nguyên dương ). Phương trình này có thể có vô số nghiệm. Tuy nhiên ở đây ta chỉ quan tâm các nghiệm (x,y,z) mà x,y,z là các số nguyên tố. Yêu cầu: Cho số nguyên dương N, hãy tìm tất cả các nghiệm (x,y,z) trong đó x < y < z. INPUT: Một dòng duy nhất ghi một số nguyên dương N ( N < 5000 ). OUTPUT: Gồm N dòng, dòng thứ i cho biết bộ nghiệm (x,y,z) thứ i tìm được. Nếu phương trình không có nghiệm nào thì in ra -1. Ví dụ input 5 output -1 input 8 output 2 3 3 c++ he;p
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