Area of a square = Side × Side
Side = 7x-3
Area of the square = (7x-3) × (7x-3)
= 7x(7x-3) -3(7x-3)
= 49x^2 -21x -21x +9
=49x^2 -42x +9
Answer:
11.42 boxes
Step-by-step explanation:
For the first box bought, there is a 100% chance of getting a unique toy (since you still don't have any). E₁ = 1.
After that, there is a 4 in 5 chance of getting a unique toy from the next box, the expected number of boxes required is:

For the next unique toy, there is now a 3 in 5 chance of getting it:

Following that logic, there is a 2 in 5 chance of getting the 4th unique toy:

Finally, there is a 1 in 5 chance to get the last unique toy:

The expected number of boxes to obtain a full set is:

Step-by-step explanation:
3/4 × 3/3 = 9/12
3/4 × 2/2 = 6/8
Answer:
-3.09 per hour
Step-by-step explanation:
if you mean that it went down from 0° to -131.5° in 42.5 hours, divide -131.5 by 42.5 (-131.5/42.5) which gives 3.09