
That's 7.68% = 7.7% (rounded)
Note: C(5, 4) is the number of combinations of 5 things taken 4 at a time. You may have seen this written as

In general,
The vertex is (0,-8)
im not sure about axis of symmetry but i don’t think it has one
98000*0.15 is how you would find out how much he has to pay for tax, which is 14700. since you didn't post plan b, this is all i can do.
Answer:
Area = 16.8 * 7 / 2 = 58.8 ft2
Step-by-step explanation:
Have
18.2^2 = 7^2 + a^2
-> a^2 = 18.2^2 - 7^2
-> a^2 = 282.24
-> a = 16.8
Area = 16.8 * 7 / 2 = 58.8 ft2