Answer:

or

Step-by-step explanation:
Hello!
Use the quadratic formula: 
First, let's convert our equation to standard form of a Quadratic: ax² + bx + c = 0
3x² = 80
3x² - 80 = 0
Note, thats the value of b will be 0, as there is no "bx"
Now, solve:
Plug in values
Simplify the radical (Discriminant)
Pull out perfect squares
Reduce factors
The solutions are 
You answer for a. show be 200+600-1 should e lil tj
The final amount if $10 000 invested for 6 years at 4% compounded quarterly is $12,697
<h3>Compound interest</h3>
The formula for calculating the compound interest is given as:
A = P(1+r/n)^nt
Given the following parameters
A = 10000(1+0.04/4)^4(6)
A = 10000(1+0.01)^24
A = 10000(1.01)^24
A = 1.2697(10,000)
A = $12,697
Hence the final amount if $10 000 invested for 6 years at 4% compounded quarterly is $12,697
Learn more on compound interest here: brainly.com/question/24924853
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The answer would ne answer choice b. I don't know what the last answer choice was though.
Step-by-step explanation:
m< AOC = 90°
m< AOB +m<BOC = 90°
6x-12+3x +30 = 90°
9x +18° = 90°
9x = 90- 18° = 72°
x = 8°
m<AOB =6(8)-12 = 48-12 = 36°