In each case, find the equation of the parabola with a vertex at the origin and the given directrix.
a. 2x – 3 = 0 b. 5y – 2 = 0
c. x = –ñ3 d. 3

Two customers went to a post office. first customer paid $12 for 14 and 5 envelopes the second paid 24.80 for 10 postcards and 15 envelopes. what is cost of each envelope?

Which number line represents the solution set for the inequality -1/2x> 24?

Astudent draws two parabolas on graph paper. both parabolas cross the x-axis at (-4, 0) and (6,0). the y-intercept of thefirst parabola is (0, –12). the y-intercept of the second parabola is (0-24). what is the positive difference between the avalues for the two functions that describe the parabolas? write your answer as a decimal rounded to the nearest tenth.