Given:
The figure of a right triangle.
To find:
The length of AB.
Solution:
In a right angle triangle,

Using this trigonometric ratio for the given triangle, we get





Therefore, the length of AB is 5 units.
So, u would start by expanding the bracket and ignoring the 2 at the moment.
(x+9)(x+9)= x^2-18x+81(using the foil method!
Then u would put 2 at the front to get:
2(x^2+18x+81)
= 2x^2+36x+162
General Idea:


Conclusion:
Amount of interest that Lucy to be charged in a typical month is <u>$9.75</u>
The answer is for the formula