The heck, what math are you in?
Answer:
translation
Step-by-step explanation:
because a reflection across the x-axis is not right, and neither is across the y-axis. The triangle was also not rotated 90 degrees. It was translated 8 units to the right and 4 units up.
The desired number is the difference between the number of messages sent by the 16th day and the number sent by the 9th day:
... n = t(16) - t(9)
... n = (40×√16) - (40×√9)
... n = 40×(4 - 3) = 40
40 text messages were sent between the ninth and sixteenth day of the month.
What do you need help with?