Let x = Barbie's number
1/3 x -20 = 72
1/3 x = 92
x = 92*3=276
Area=lenght times widht
area/length=width
(4x²+12x)/(4x)=width
we can factor out the 4x
4x²+12x=4x(x+3)
so the width is x+3
Answer:
No it is still 11 feet from the water at 2 seconds
2.1651 seconds is when it will hit the water
Step-by-step explanation:
h(t) = -16 t^2 +75
This is the formula for the distance
The -16t^2 is due to gravity and the 75 is the height above the bridge
We want to know the height a t =2
h(2) = -16 (2)^2 +75
h(2) =-64 +75
h(2) = 11
The rock will be 11 ft above the water
When will the rock hit the water
h = 0
0 = -16 t^2 +75
Subtract 75 from each side
-75 = -16t^2 +75-75
-75 = -16t^2
Divide by -16
-75/-16 = -16t^2 /-16
75/16 = t^2
Take the square root of each side. We only take the positive square root since time must be positive
sqrt(75/16) =t
5/4 sqrt(3) = t
2.1651 seconds = t
