Answer:
$5903.39
Step-by-step explanation:
This can be solve using compound interest formula. The formula is:

Where
F is the future amount (what we are looking for)
P is the present amount (which is 4800)
r is the rate of compound interest per year, in decimal (3% per year, 3/100 = 0.03)
t is the time in years ( t = 7)
Now we substitute these values into the formula and find F:

So, Colin would have $5903.39 after 7 years, in his account.
If BE=30 then you would have to find out what x is. 8+12=20 so all you need is 10 more to equal BE.
There is a trig identity called the sum of 2 angles for sin its<span>
sin(a+b)=sin(a)cos(b)+cos(a)(sin(b)
</span>
You will need to use it. So in your question split the 4x in 2 equal parts 2x and 2x
<span>
</span><span>sin(4x)=sin(2x+2x)
</span>Now using the expansion above you will get
<span>sin(2x+2x)=sin(2x)×cos(2x)+cos(2x)×sin(2x)
</span>And it will simplify to
<span><span>2sin(2x)cos(2x)
I hope this helps you! Good luck :)</span></span>