5x(x-3)+7x-21=0 ;         7x^3-56x^2+9x-72=0;         (y^2-5y)^2=30y-6y^2;     9-25x^2+90x-81=0;     помогите пожалуйста решить

Составте викторину о еде на русском,а с английским сама разберусь!!!

Заранее спасибо!!!

TEENAGER DAVID BOLTON has just put ￡9,000 in the bank – after only six months of part-time work as computer consultant. The electronics expert from Croydon, Sounth London, is establishing a reputation as one of the country’s top troubleshooters – the person to call if no one else can cope. For David, 15, his first steps to fame and fortune began when he was only nine, when his parents bought him a computer, a ZX-90. “I soon learned to program it. I needed something bigger, so I had to save for ages to buy an Amstrad.” It was only about a year ago, however, that he decided to get serious about computing. He went to night school to learn how to write business programs, and did a correspondence course with an American college. He got in touch with a computer saller, Etlec, who were so impressed they gave him computers and software worth more than ￡3,000. In return, he has to send them a monthly report saying what he has done and what his plans are. He helps companies by suggesting which computers they should buy, and by writing individual programs for them. He can work more quickly than many older professionals. In one case, he went to a company where a professional programmer worked for six months and couldn’t find the problem. David finished the job in five days. It is because of work of this standard that in the short period he has been in business David has made about ￡9,000. With it he has bought more equipment. How did he do it? “You have to be ambitious, and you have to really want to get to the top. Believe in yourself, and tell yourself that you’re the best.”

сколько целых чисел расположено между числами 0 И 24

пропускная способность некоторого канала связи равна 128000 бит/сек. сколько времени займет передача файла объёмом 500 Кбайт по этому каналу?