The last option seems the best one: the figure is composed of a square/rectangle and a triangle. The area of the rectangle is the product of its dimension (i.e. 
), while the area of the triangle is half the product of the base and height (
).
The sum of the two areas is the area of the composite shape.
I'm going to rewrite f(t) to make it a little easier to use the power rule:
Now just take the derivative using the power rule:
Since they ask for f'(a), we need to replace the t's with a's:
3. 4y-3
because 1/3*12y - 1/3*9 = 4y - 3
Answer:
15s
Step-by-step explanation:
Write like so:
54m = 9s
90m = x
Cross multiply:
(90*9)=(54x)
810 = 54x
Divide both sides by 54:
810/54 = 54x/54
15 seconds = x
