Answer:

Step-by-step explanation:
Compound interest:
The compound interest formula is given by:

Where A(t) is the amount of money after t years, P is the principal(the initial sum of money), r is the interest rate(as a decimal value), n is the number of times that interest is compounded per year and t is the time in years for which the money is invested or borrowed.
$12000 cash
This means that 
Compounded at 4% interest annually.
This means that 
What equation will calculate the value in x years?




In the figure below
1) Using the theorem of similar triangles (ΔBXY and ΔBAC),

Where

Thus,

thus, BC = 7.5
2) BX = 9, BA = 15, BY = 15, YC = y
In the above diagram,

Thus, from the theorem of similar triangles,

solving for y, we have

thus, YC = 10.
Yes, your work is correct.
The diagram does illustrate x²+6x+9=72. This is also represented by
(x+3)² = 72
We can take the square root of both sides:

When we evaluate this, the answers are x = -11.5 or x = 5.5.
Answer:
a) Similar triangles are triangles with the same shape but not necessarily the same size
b) 15/45 = 8/x
1/3 = 8/x (simplify the 15/45)
x = 8 * 3 (cross multiplication)
x = 24
c) y^2 = 15^2 + 8^2 (Pythagoras theorem)
y = *square root of* 15^2 + 8^2
y = 17
1/3 = 17/z
z = 17 * 3 (cross multiplication)
z = 51