Afootball is kicked at ground level with an initial velocity of 64 feet per second

find the height after 3 second and use one of the three forms and say which one would be the best to use and why

y= -16t^2+64t
y= -16(t-2)^2 + 64
y= -16t(t-4)

The height of the football is 48 feet after 3 seconds

The first equation y = -16t² + 64t is the best

Step-by-step explanation:

* Lets explain how to solve the problem

- The equation of motion of an object on air without any

 external force is y = ut + 1/2 at², where y is the height of the

 object from the ground, u is the initial velocity, a is the

 acceleration of gravity and t is the time

* Lets solve the problem

- A football is kicked at ground level with an initial velocity of

 64 feet per second

∴ u = 64 feet per seconds

∵ The football is kicked upward

∴ a = -32 feet per seconds²

∵ y = ut + 1/2 at²

∴ y = 64t + 1/2 (-32)t²

∴ y = 64t - 16t²

* We will use the first equation y = -16t² + 64t

∵ y = -16t² + 64t

- We need to find the height of the football after 3 seconds

∵ t = 3 seconds

∴ y = -16(3)² + 64(3)

∴ y = 48

∵ y represents the height of the football

∴ The height of the football is 48 feet after 3 seconds

5x + 3y = - 4

step-by-step explanation:

the equation of a line in standard form is

ax + by = c ( a is a positive integer and b, c are integers )

express the line first of all in slope- intercept form

y = mx + c ( m is the slope and c the y-intercept )

to calculate m use the gradient formula

m = ( y₂ - y₁ ) / ( x₂ - x₁ )

with (x₁, y₁ ) = (7, - 3) and (x₂, y₂ ) = (4, - 8)

m = = -

y = - x + c ← is the partial equation

to find c substitute either of the 2 points into the partial equation

using (4, - 8 ), then

- 8 = - + c ⇒ c = -

y = - x - ← in slope-intercept form

multiply all terms by 3 to eliminate the fractions

3y = - 5x - 4 ( add 5x to both sides )

5x + 3y = - 4 ← in standard form