1.The Ford car left Hanoi for Nghe An and the Audi car left Nghe An for Hanoi at the same time. The ratio of their speeds (the Ford car to the Audi car) was 4:3. The Ford car decreased its speed by 25% and the Audi car increased its speed by 25% after they had passed each other. When the Ford car reached Nghe An, the Audi car was still 20 km away from Hanoi. The distance between Hanoi and Nghe An is .... km

2.The smallest value of A= \(\frac{x-y}{x^{4}+y^{4}+6}\) is.....

The Ford car left Hanoi for Nghe An and the Audi car left Nghe An for Ha Noi at the same time. The ratio of their speeds (the Ford car to the Audi car) was 4 : 3. The Ford decreased its speed by 25% and the Audi car increased its speed by 25% after they had passed each other.
When the Ford car reached Nghe An, the Audi car was still 20km away from Hanoi. The distance between Hanoi and Nghe An is ...... km

Trả lời kỹ càng giúp mjk nha :))) 

Nghiêm cấm mấy thành phần trả lời I don't know vv.... Biết hẵng trả lời nha :)))

1. Give the correct form of the verbs in brackets.

a, My uncle ............... (take) me to a piano concert last night. It ............... (be) nice. I really ............... (enjoy) the concert.

b, American Engineer Henry Ford ............... (start) the Ford Motor Company in 1903. Ford ............... (call) the car the Ford Model T. He............... (start) making the Ford Model T in Detroit I 1908. Millions of people ............... (buy) the car and Ford ............... (become) a very rich man.

III. Put the correct tense of each verb in brackets.

   a. My uncle ( take ) ……………….. me to a piano concert last night. It ( be) …………….. a pleasant evening. I ( meet) ……………….. many interesting people. The weather ( be) ……… nice. I really ( enjoy) …………… the concert.

   b. American engineer Henry Ford ( start) …………….. the Ford Motor Company in 1903. Ford ( produce) …………………. the first cheap motor car. He ( call) ……………….. the car the Ford Model T. He ( start) ………………… making the Ford Model T in Detroit in 1908. Millions of people ( buy) ……………….. the car and Ford ( become) …………………. a very rich man.

    c. Two people ( die) ……………… in a fire in Ellis Street, Oldport yesterday moring. They

 ( be) ………………… Herbert and Molly Paynter, a couple in their seventies. The fire ( start) ………………….. at 3.20 a.m. A neighbour, Mr.Aziz ( see) …………… the flames and ( call) ……………….. the fire brigade. He also ( try) ……………… to get into the house and rescue his neighbours, but the heat ( be) ………………….. too great. The fire brigade ( arrive) ………………… in five minutes. Twenty fire fighters ( flight) ……………… the fire and finally ( bring) …………………. it under control. Two fire- fighters ( enter) ………………. burning building but ( find) ………………. the couple dead.