Can I get help on this graph question

Write the expression in simplified radical form. show all steps and work including any foil method work. (hint: use the conjugate. no decimal answers.) (9-2√3)/(12+√3)

Imogene invested $8,000 in a bank account that pays 8 percent simple interest at the end of each year. her friend invested the same amount in stocks where the growth of the investment is represented as 2,000 times the square root of 2 less than the time lapsed in years. if y1 and y2 represent the amount earned in dollars and t is the time lapsed in years, which system of equations correctly represents the situation?

Atriangle has a side lengths of 18cm, 80 cm and 81cm. classify it as acute obtuse or right?