Mark wants to maintain an average of 70 on his math tests to remain eligible for sports. so far, he earned scores of 68, 75, 74, 82, and 88. what is the lowest score he can earn on the next test to have an average of at least a 70?

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?