10. to which subsets of the real numbers does the number √7 belong? [] rational numbers [] irrational numbers [] whole numbers, integers, rational numbers [] whole numbers, natural numbers, integers 11. which sum or difference is equivalent to the following expression? 15x - 20 5 [] 15x - 4 [] 10x - 15 [] 3x - 4 [] 3x - 20

Offering 30 if a plus b plus c equals 68 and ab plus bc plus ca equals 1121, where a, b, and c are all prime numbers, find the value of abc. the answer is 1978 but i need an explanation on how to get that.

Solve the following simultaneous equation by using an algebraic method (either substitution or elimination) 2x + 3y=-4 4x-y=11

Monitors manufactured by tsi electronics have life spans that have a normal distribution with a standard deviation of 1800 hours and a mean life span of 20,000 hours. if a monitor is selected at random, find the probability that the life span of the monitor will be more than 17,659 hours. round your answer to four decimal places.