Amount saved:50I60I70l80l AND ON......
......weeks......:0..I1...l2..l3..l ..........AND ON
amount saved =x
weeks=y
after every y+10=x
Rearrange to: x^2 + 18x - 25 = 0
Then factorise (I like to do it by completing the square):
(x + 9)^2 -81 -25 = 0
(x + 9)^2 = 106
x + 9 = sqrt(106)
The sol'ns are:
x = -9 + and - sqrt(106)
Answer: 24 commercials
Step-by-step explanation: An hour is 60 minutes. She'll watch 120 minutes of the game. 120 divided by 5 is 24. Good luck! :D