Which of the following is a reflection of (2, 4) across the x-axis?
A (2,-4)
C (-2, 4)
B (-2,-4)
D (4,2)

An investment decreases in value by 30% in the first year and decreases by 40% in the second year. what is the percent decrease in percentage in the investment after two years

Louis wants to carpet the rectangular floor of his basement the basement has an area of 864 square feet the width of the basement is 2/3 its length what is the length of lewis's basement

The pyraminx is a rubik's cube-type toy in the shape of a tetrahedron. the pyraminx shown below has edges 15\,\text{cm}15cm long and vertical height h=12.2\,\text{cm}h=12.2cm. the triangle drawn with dashed lines is a right triangle. what is the distance rr? round your answer to the nearest tenth.