Answer: 
Step-by-step explanation:
Given
Population of dust particle doubles every 30 minutes
If the initial sample is 21 grams
The model to predict the population will be

Where t=time in hours
A day has 24 hours . So, for 2 days time is 48 hours
Population is given by
1 d=24
2 m=60
3 y=y(365)
4 x=x(50.10)
5 n=n(2500)
6 1+1=2
Here is the problem.....√(15x + 10) = 2x+3
to remove the square root, we do the opposite which is to square everything.
(√(15x + 10))² = (2x + 3)² (the square negates the square root)
15x + 10 = (2x +3)(2x + 3) (use the distributive property to continue)
15x + 10 = 4x² + 6x + 6x + 9 (combine like terms)
15x + 10 = 4x² + 12x + 9 (subtract 15x and 10 from each side)
-15x - 10 -15x - 10
0 = 4x² - 3x - 1 (factor completely)
(x - 1) (4x + 1) (set each to equal 0)
x - 1 = 0 4x + 1 = 0
x = 1 4x = -1
x = -1/4
place both into the equation to check for reasonableness...we see the negative number is not reasonable, but the x value of 1 is a solution.
answer is 1
Answer:
4.8 inches
Step-by-step explanation:
Given: The largest frog in the world is goliath which is 12 inches long.
The smallest frog is about 2.5 as long as the goliath.
Lets assume the length of smallest frog be "x".
As given, smallest frog is about 2.5 as long as the goliath.
∴ we can form equation as 
Solving the equation to find the value of x

Dividing both side by 2.5
⇒ 
∴ 
Hence, the length of smallest frog is 4.8 inches.