She would have done 512 jumping jacks on the 10th day.
It is a similar triangle so the side length of the smaller triangle (x and x-2) are in the same ratio as the bigger triangle (2x+5 and 2x-1). As the ratio is the same, you can equate them and solve for x.
Answer:
96
Step-by-step explanation:
U is the midpoint of TV, so mTU is half of mTV or mTV = 2 * mTU, so
mTV = 2 * mTU
11x + 8 = 2 (6x)
11x + 8 = 12x
8 = x
mTV = 11x + 8 = 11(8) + 8 = 88 + 8 = 96