The x-coordinate is negative, and the y-coordinate is negative.
This is because the y-axis is vertical, so reflecting across it means you will change the sign of the x-value, and the sign of the y-value will stay constant. Since we start off with a positive x and negative y, we will end up with a negative x and negative y.
It's 11040 plants because 92 percent of 12000 is 11040. (Idk if this is the best reasoning but :/)
Every Triangle adds up to 180 degrees
180 - 63 = 117 | 117 - 56 = 61 so x = 61
12y + 3 = 51 so y = 4