Honestly? Just review your notes and try to work out the problems yourself before taking a look at the answer. You can also google specific topics that the test will cover and try the practice problems.
Answer:
A. 2 distinct roots.
Step-by-step explanation:
2x^2 + 8x + 3 = 0
Finding the discriminant:
b^2 - 4ac = 8^2 - 4 * 2 * 3
= 64 - 24
= 40
The discriminant is positive but not a perfect square
So there are 2 distinct ,real, irrational roots.
The half life formula is :

where N(t) = remaining quantity after t years
No = Original Quantity
t = time in years
T = half life in years
From the problem, we have :
N(t) = 30 grams
No = 100 grams
T = 674
Solve for t :

Take ln of both sides :

The answer is t = 1170.71 years
4.561, 4.562, 4.563, 4.564, 4.560