You would split out the velocity into x and y components.
X component: 5.6cos(73)= 1.637i
Y component: 5.6sin(73)= 5.355j
Therefore velocity in its component form is 1.637i + 5.355j ft/s
You can eliminate 81 because we know 
The dot is on approximately 9.32 (my estimate) so I would square that number:
(9.32)² = 86.8624 so if you round this you get 87
Answer:
20/5 = x /4 x = 80/5 = 16
x - 10 / 39 = 5/15 = 1/3
3x - 30 = 39
3x = 69
x = 23
(2x + 10 ) * 4 = 10 *(x + 3)
8x + 40 = 10x + 30
2x = 10
x = 4.
AE = 2(5) + 10 = 20, hope this helped.
There are no real roots for a negative number, so -81 has no real roots, if the number is 81 however, then the tow roots are 9
