Selling price of app per user = $10 per month
Total no. of user in first month = 10
To tal no. of user added per month = 7
We have to find how much money is earned in one year
So the formula is n/2 * (2a +(n-1)d)
Here we have n = 12 which is total no. of months
a = 100 , which is money earned in one month
d = 70 , which is increase in money earned per month
So money earned in a year comes out to be 5820
Distribute the .25 to get .25x + 1 - 3 = 28
Then simplify to get .25x - 2 = 28
Move the two to the right to get .25x = 30
Then divide to leave x: 30 / .25 = 120
X = 120
Answer: k=3
Step-by-step explanation:
33/99 divide top and bottom by 11
33/99divided by 11/11
=3/9
Split it up
3x^2+12x-5x-20
group
(3x^2+12x)+(-5x-20)
factor
(3x)(x+4)+(-5)(x+4)
undistribute (x+4) like ab+ac=a(b+c)
(3x-5)(x+4)
The answer is 37 years old.
I = -425x² + 45500x -650000
I = 450000
-425x² + 45500x -650000 = 450000
-425x² + 45500x - 650000 - 450000 = 0
-425x² + 45500x - 1100000 = 0
Divide all factors by 25:
- 17x² + 1820x - 44000 = 0
This is quadratic equation (ax² + bx + c = 0)

Since, the youngest age is needed, the correct answer is x = 37