If $1=Rs. 102.50 and £ 1=Rs. 140, how many dollars equals £ 5?

The graph below shows the height of a projectile t seconds after it is launched. if acceleration due to gravity is -16 ft/s2, which equation models the height of the projectile correctly?

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?

*segment an is an altitude of right ? abc with a right angle at a. if ab = 2root 5 in and nc = 1 in, find bn, an, ac.