let's check how much is it after 2 years firstly.

Brian invested the money for 6 years, so now let's check how much is that for the remaining 4 years.


Find the coordinates of the vertex of the following parabola using graphing
technology. Write your answer as an (x, y) point.
y = 3x^2-12x + 21 it’s -1
In the given diagram, the traingles USW and UTV are similar triangles and thus the following ratio equality applies to them.
..........(Equation 1)
Checking the diagram given, we see that:
VT=y, WS=22, VU=8, ST=x-2
WU=WV+VU=12+8=20
TU=5
SU=ST+TU=(x-2)+5=x+3
Thus, substituting the required values in (Equation 1) we get:

Now, as can be clearly seen, to find y we will use the first two ratios as:


In a similar manner, to find the value of x we can use the last two ratios:

After cross multiplication we get:

Which can be simplified as:

Thus, 
Therefore, the required answer is:
x=9.5 and y=8.8