The high school courtesy club bought red and black ink pens for teacher appreciation day. the club bought 75 pens in all. each black pen cost $1.75, and each red pen cost $2.00. the club spent $137 altogether for the pens. how many black pens did the club buy? 13 23 48 52

The first few steps in solving the quadratic equation 9x2 + 49x = 22 ? 5x by completing the square are shown. 9x2 + 49x = 22 ? 5x 9x2 + 54x = 22 9(x2 + 6x) = 22 which is the best step to do next to solve the equation by completing the square? 9(x2 + 6x + 3) = 25 9(x2 + 6x + 3) = 49 9(x2 + 6x + 9) = 31 9(x2 + 6x + 9) = 103