有代表性的数学题..docVIP

1.y=2x2+7x – 3 x y 2. The figure above shows the graph of a function f, defined by f(x)=|2x|+4 for all numbers x. For which of the following functions g defined for all numbers x does the graph of g intersect the graph of f ? A g(x)x–2 B g(x)x3 C g(x)2x – 2 D g(x)2x3 E g(x)3x – 2 3.Each employee of a certain company is in either Department X or Department Y, and there are more than twice as many employees in Department X as in Department Y. The average (arithmetic mean) salary is $25,000 for the employees in Department X and is $35,000 for the employees in Department Y. Which of the following amounts could be the average salary for all of the employees in the company? Indicate all such amounts. A $26,000 B $28,000 C $29,000 D $30,000 E $31,000 F $32,000 G $34,000 4.Working alone at its constant rate, machine A produces k car parts in 10 minutes. Working alone at its constant rate, machine B produces k car parts in 15 minutes. How many minutes does it take machines A and B, working simultaneously at their respective constant rates, to produce k car parts? ____________minutes 1)If the dollar amount of sales at Store P was $800,000 for 2006, what was the dollar amount of sales at that store for 2008 ? A $727,200 B $792,000 C $800,000 D $880,000 E $968,000 2)At Store T, the dollar amount of sales for 2007 was what percent of the dollar amount of sales for 2008 ? Give your answer to the nearest 0.1 percent. ___________% 3)Which of the following statements must be true? Indicate all such statements. A For 2008 the dollar amount of sales at Store R was greater than that at each of the other four stores. B The dollar amount of sales at Store S for 2008 was 22 percent less than that for 2006. C The dollar amount of sales at Store R for 2008 was more than 17 percent greater than that for 2006. 6.A certain store sells two types of pens: one type for $2 per pen and the other type for $3 per pen. If a customer can spend up to $25 to buy pens at the store and there i