It is one of the checks the legislative branch holds over the executive branch. How does the commerce power differ from the currency power? The commerce power relates to trade, both interstate and international, while the currency power relates to providing a stable monetary system.
Looks good to me. Calculation is correct. Although you might want to add to #1 your description; that the width of the rectangle is the circumference of the circle (w = 2πr) and that you add the surfaces together to get the total surface area.
total surface area = area of rectangular part + area of circular parts
SA = 2πrL + 2πr²
B
Explanation: Associative property basically means that the numbers stay in the same spot but the parentheses move
T=650mi(hr/50mi)=13 hr
t-1=12 hr
12=650/(50+v) multiply both sides by 50+v
600+12v=650 subtract 600 from both sides
12v=50 divide both sides by 12
v=25/6 mph
v≈4.17mph
