Area of a square = length²
A = x²
16 = x²; x = 4
dA/dx = 2x cm²/s
dx/dt = 6 cm/s
Using chain rule:
dA/dt = dA/dx * dx/dt
dA/dt = 2x * 6
dA/dt = 12x
At x = 4,
dA/dt = 12(4) = 48 cm²/s
2=4, 3=6, 4=8, 5=10
inches will be x and length will be y you multiply x by 2 to get y
Square root of 100 is 10 feet/side
1 pound is 0.453592 kilograms
so 8.4 pounds is 3.81018 kilograms
You would cross multiply and make sure the units are lined up with each other
1

then you would cross multiply and get 3.81018
The length of the actual car is 240 inches
1/25 = 9.6/x
25x9.6/1=240
x=240 inches
Hope this helped you! :D