cho em hỏi chỗ Δ' = b² - 3ac thì em ra m² + 2m - 4 là em sai ở đâu ạ ?

The number of cars in the city .......... by 25 percent. A. Has rising B. Have risen C. Has raised D. Was risen

a, 1000mm; 100cm; 10dm;......... b, 10giờ 15phút ; 11giờ 30; 12 giờ 45phút.......... c, 102kg; 120kg; 201kg;.........

Giúp với ạ,đề bài là chuyển sang bị động và điền thì ạ

a . Tìm từ đông nghĩa với từ đen dùng để nói về : con mèo , con chó , con ngựa , đôi mắt b . đặt câu với mỗi từ vừa tìm được trước 6 : 30

Tam giác ABC vuông tại A biết tan B =2.Tính các tỉ số lượng giác của B

Hòa tan 6,5 gam kẽm vào axit clohdric 7,3% a) viết pthh b) tính khí ở đktc C) tính khối lượng axit cần dùng

G = x(6-x) + 74 + x Tìm giá trị lớn nhất

2: Put the verbs in the present continuous tense. 1. He a book about American history at the moment.(read) 2. Why ……………… you ? What’s so funny?(laugh) 3. I can’t help younow. I (work) 4. Ohno! It again.(rain) 5. ……….……….. you the TV or can I turn it off?(watch) 6. Bill ………………… to drive at the moment.Hisfather him. (learn, teach) 7. Listen!The neighbors an argument again. (have) 8. Sally her new T-shirt today.(wear) 9. Robert! What……………… you here? (do) 10. I very well at the moment. (notsleep) 3: Put the verbs in the present simple tense or present continuous tense. 1. Emily lives and works in Parisbutshe (have) a holiday in England at themoment. 2. I wonder why theneighbor’sdog (bark) again. Maybe there is aburglar! 3. Ann (get) up at seven o’clock everymorning. 4. Thenshe (go) to have a shower beforebreakfast. 5. Thenshe (drive) to the beach and stays allday. 6. She (not/ work) because she won the lottery lastyear. 7. Why (you/ learn) English thisyear? 8. I (live) with my sister for two months because she is pregnant and I can helpher. 9. What (you/wear) now? In that way, I will recognize you at theairport. 10. Kate is in the kitchen and verystressed!She (cook) dinner for 30 people. 4: Put the verbs in the present simple tense or present continuous tense. 1. Where’sTim? He (listen) to a new CD in hisroom. 2. Don’t forget to take your umbrella with you to London. You knowitalways (rain) there. 3. Emily (work) hard all daybutshe (not work) at themoment. 4. Look! Thatboy (run) after thebus. He (want) to catch it. 5. He (speak) French so wellbecausehe (come) fromFrance. 6. Look! The boss (come).We (meet) him in an hour and nothing is ready! 7. you usually (go) away forChristmas or you (stay) athome? 8. She(hold) someroses. They (smell)lovely. 9. Look! It (snow) again. Italways (snow) in thiscountry. 10. Sally (swim) very well,but she (not run) very fast. B. Exercise 5: Read the following passage and mark the letter A, B, c, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks. We first learn about loving and caring relationships from our families. Family is defined as a domestic group of people with some degree of kinship - whether through blood, marriage, or adoption. Ideally, each child is nurtured, respected, and grows up to care for others and develop strong andhealthy relationships. This does not mean that it is always easy to make and keep friends; it just means that we share the goal of having strongrelationships. "Family" includes your siblings and parents, as well as relatives who you may not interact with every day, such as your cousins, aunts, uncles, grandparents, and stepparents. These are probably the people you are closest to and with whom you spend the most time. Having healthy relationships with your family members is both important and difficult. Families in the 21stcentury come in all shapes and sizes: traditional, single parent, blended (more than one family together in the same house), and gay and lesbian parents - just to name a few. No matter the "type" of family you have, there are going to be highs and lows - good times and bad. Many times, however, families become blocked in their relationships by hurt, anger, mistrust, and confusion. These are natural and normal, and few families do not have at least a few experiences with them. The worst time for most families, is during a divorce. By making a few simple changes in the way we look at the world and deal with other people, it is possible to create happier, more stable relationships. Families need to be units of mutual caring and support; they can be sources of lifelong strength for allindividuals. (Adapted from http://www.pamf.org/) Question 1: What is the main idea of the passage? A. The role of members infamily. B. The healthy relationships among members infamily. C. The importance of sharing housework in afamily. D. The importance of having children in afamily. Question 2: According to the passage, which example below is probably NOT TRUE about the definition of family? A. wife &husbandrelationship B. god-mother & god-sonrelationship C. step-father &daughterrelationship D. nanny & babyrelationship Question 3: Ideally, each child is nurtured, respected, and growsupto ? A. to be concerned about the people aroundthem. B. to keep in touch with the people aroundthem. C. to keep a track of the people aroundthem. D. to be familiar with the people aroundthem. Question 4: Which of the following is closest in meaning to “siblings" in paragraph 2? A. husband&wife B. brothers & sisters C.chilren D.friends Question 5: What does the word "These" in paragraph 2 refer to? A. highsand lows B. good and bad times C.relationships D.feelings Giúp em với ạ, em đang ko bt phải làm thế nào!!!!!

cho A = x nhân (1 cộng x) - x mũ 2 nhân (1-x) cộng x mũ 3 nhân (x mũ 2 -1) chứng minh rằng với 2 giá trị đối nhau của x thì biết A có bao nhiêu giá trị