Đáp án+Giải thích các bước giải:
`a)`
`x^3-3x^2-4x+12`
`=x^2(x-3)-4(x-3)`
`=(x^2-4)(x-3)`
`=(x-2)(x+2)(x-3)`
`b)`
`x^3+xy^2-16x+2x^2y`
`=x(x^2+y^2-16+2xy)`
`=x[(x^2+2xy+y^2)-4]`
`=x[(x+y)^2-2^2]`
`=x(x+y+2)(x+y-2)`
`c)`
`x^3-3x^2-4(x-3)`
a,`x^3 - 3x^2 - 4x + 12 `
`=(x-3)(x^2 - 4)`
`=(x-3)(x-2)(x+2)` hđt ` a^2 - b^2 = (a-b)(a+b)`
b)
`x^3+xy^2−16x+2x^2y`
`=x^3+xy^2-16x+2x^2y`
`=x(x^2+y^2−16+2xy)`
`=x[(x^2+2xy+y^2)−4]`
`=x[(x+y)^2−2^2]`
`=x(x+y+2)(x+y−2)`
c)
`x^3−3x^2−4(x−3)`
`=x^2(x−3)−4(x−3)`
`=(x^2−4)(x−3)`
`=(x−2)(x+2)(x−3)`
Điền vào chỗ trống: a)... + ... = HCl + ... b)... + ... = Fe(OH)3 + ... c)... + ... = Ba(OH)2 + ... d)... + ... = CuSO4 + ...
cách chụp hình trên máy tính khi không có cam
tìm lỗi sai 1.that's a friend who is looking after us 2. the doctor suggested that she does exercises regularly and go to bed as early as possible
(2 và 1/3+ 3 và1/2) nhân 0,2+ 25%
Trong các chính sách cai chị của phòng kiến phương Bắc , chính sách nào thâm hiểm nhất
she ( wear)______________________ a red pullover and black jeans to day Alan ( get up ).............. at seven o'clock every morning Tuan ( have )............................... a shower before breakfast my father often ( drive)........... to the office he ( not/work)................ because he is old why ( you/learn).......................english this year? I ( live).............with my sister for a month because she í pregnant and I can help her
Giúp mình câu 48 phần b và đ nha
Bài 1: Tính khối lượng kết tủa và khối lượng các chất trong dung dịch khi cho dung dịch chứa 17,1 gam Ba(OH)2 tác dụng với 4,48 lít SO2 (đktc). Bài 2: Tính khối lượng kết tủa và khối lượng các chất trong dung dịch khi cho dung dịch chứa 42,75 gam Ba(OH)2 tác dụng với 6,72 lít SO2 (đktc)
Tính: a.(x+3y)(x ² - 2xy+y) b.(6x+1) ²+(6x-1) ²-2(36x ²-1) c.(2x^5-5x ³+x ²+3x-1):(x ²-1) d.(x ²-81+y ²-2xy):(x-y-9)
1. If I were you, I ..................... do something to prevent him from littering.) * A. would B. did C. will D. do 2. Many aquatic animals and plants.............. due to the oil spill. * A. dies B. having died C. have died D. to have died 3. “Do you need an umbrella to go out?” Hoa’s mother asked. * A. Hoa’s mother asked if you need an umbrella to go out. B. Hoa’s mother asked if you need an umbrella to go out. C. Hoa’s mother asked if you needed an umbrella to go out. D. Hoa’s mother asked if she needed an umbrella to go out. 4. You will do the test well. You will review them all hard. * A. If you reviewed them all hard, you will do the test well. B. If you review them all hard, you will not do the test well. C. If you review them all hard, you will do the test well. D. If you will review them all hard, you will do the test well. 5. He drives the most ………………..in the race. * A. quick B. quickly C. quicker D. more quicker 6. The librarian asked us ...................so much noise. * A. don't make B. not make C. not to make D. not making 7. Laura enjoys ................... on the phone with her friends. * A. chat B. chats C. chatting D. chatted 8. The roof of the house .......................... in a storm last week. * A. was damaged B. damaged C. has damaged D. has been damaged 9. This time next week we...................around Africa. * A. are travelling B. travel C. will travel D. will be travelling 10. Did the boys give food to homeless people yesterday? * A. Was did the boys give food to homeless people yesterday? B. Was food given to homeless people yesterday? C. Was food give to homeless people yesterday? D. Were food given to homeless people yesterday? 11. If I were you, I..................this work. * A. do would B. did not C. wouldn’t do D. won’t do 12. Earth .................. by the gravity of the Sun and orbits around it. * A. holds B. is holding C. held D. is held 13. Would you mind..............me a hand? * A. giving B. give C.to give D. have given 14. We don’t have a map, so we get lost. * A. If we have a map, we wouldn't get lost. B. If we don’t have a map, we will get lost. C. If we had a map, we wouldn't get lost. D. If we had a map, we won't get lost. 15.By the time we ........................ to the cinema, the film had started. * A. gets B. had got C. has got D. got 16. Thu said that" I often play chess with my friends”. * A. Thu said that she often play chesswith her friends. B. Thu said that I often played chess with her friends. C. Thu said that I often play chess with her friends. D. Thu said that she often played chess with her friends. 17. Dick drives the ……………. in the race. * A. slow B. slowly C. more slowly D. most slowly 18. The trees can ………….. well because there is land pollution here. * A. grow B. not grow C. growing D. not grown 19. Which TV programme.........at 9 p.m tommorrow? * A.do you watch B. will you be watching C. did you watch D.will you watch 20. The farmer rides the buffalo-..................... carts loaded full of rice home. * A. draw B. drawing C. drew D. drawn
Loga.vn - Cộng Đồng Luyện Thi Trực Tuyến
