$(3a+4)^2+(4a-1)^2+(2+5a)(2-5a)$
$=9a^2+24a+16+16a^2-8a+1+4-25a^2$
$=(9a^2+16a^2-25a^2)+(24a-8a)+(16+1+4)$
$=16a+21$
Đáp án+Giải thích các bước giải:
$\underbrace{(3a+4)^2}_{a}$+$\underbrace{(4a-1)^2}_{b}$+$\underbrace{(2+5a)(2-5a)}_{c}$
`=9a^2+24a+16+16a^2-8a+1+4-25a^2`
`=16a+21`
`text{a: hằng đẳng thức số 1}` `(A+B)^2=A^2-2AB+B^2`
`text{b: hằng đẳng thức số 2}` `(A-B)^2=A^2-2AB+B^2`
`text{c: hằng đẳng thức số 3}` `(A-B)(A+B)=A^2+B^2`
`text{xin 5 sao và hay nhất nha}`
giải giúp em với ạ nhanh em đang cần gấp ạ nhanh giúp em
he's always forgetting to turn off the lights and close the door -> i wish he We weren't given any explanation for the delay ->No
Giúp em từ câu 1 đến 3 ạ. Em đang cần gấp
làm hộ em 3 bài với ạ đang cần gấp
Exercise 7: Put the verbs in brackets: past simple or past continuous. 1. I (not hear) the thunder during the storm last night because I (sleep) 2. It(be) beautiful yesterday whenwe(go) forawalkinthepark.Thesun(shine) The birds (sing) 3. My brother and sister (talk) about something when I (walk) into the room. 4. Tom (go) to his friend’s house, but the boys (not be) there. They (play)soccer in the vacant lot down the street. 5. The little boy (fall) asleep while his mother (read) him a story. 6.Ireally(enjoy) my holiday last January. Whileit(snow) in Iowa, the sun(shine) in Florida. 7. While Ted (shovel) snow from his driveway yesterday, his wife (bring) ……………..him a cup of hot chocolate. 8. John(have) a car accident last week.He(drive) down the street when suddenly a lorry (hit) his car from behind. 9. Tenyearsago,thegovernment(decide) to begin a food programme. At that time, many people in the rural area (starve) due to several years of drought. 10. They (wait) for me when I (arrive) at the station
..................................................................
Câu1 c,d câu 2 khỏi làm câu 345 làm hết dùm mình
Trong các pt sau , pt nào là pt bậc nhất 1 ẩn ? A. x mũ 2 + 2x + 1 = 0 B. 2x + y = 0 C. 3x - 5 = 0 D. 0x + 2 = 0 Giúp với mình cảm ơn
Exercise 6: Put the verbs in brackets: past simple or past continuous. 1. I (go) down the street when it began to rain. 2. At this time last year, I (attend) an English course. 3. Jim (stand) under the tree when he heard an explosion. 4. The boy fell and hurt himself while he (ride) a bicycle. 5. When we met them last year, they (live) in Santiago. 6. The tourist lost his camera while he (walk) around the city. 7. The lorry (go) very fast when it hit our car. 8. While I (study) in my room, my roommate (have) a party in the other room. 9. We (sit) in the café when they saw us. 10. I (call) Mr. Wilson at 9 last night, but he (not be) at home. He (study) at the library.
Giúp e với mọi ng ơi làm nhanh giúp e
Loga.vn - Cộng Đồng Luyện Thi Trực Tuyến
