Answer:
to estimate the sum you round to the closest number like 38 is closest to 40 so you just say you total is $40.00
difference is when say you have 30 dollars and you spend 10 the difference is 10 dollars
The dimensions are 8 ft x 8 ft.
The total area is 64 sq ft.
The dimensions of a single tile are 2 1/2 x 1 1/2
Note the equal sign. What you do to one side, you do to the other.
Do the opposite of PEMDAS. First, add 33 to both sides
4x - 33 (+33) = 7 (+33)
4x = 40
Next, divide by 4
4x/4 = 40/4
x = 40/4
x = 10
10 is your answer
hope this helps
At sea level, the pressure is 1013, that's when the altitude is at 0, sea level, let's see

so, the inital amount is 1013, when t = 0,

now, to check the atmospheric pressure at 4000, simply set t = 4000, to get A.
75 = 5 x 3 x 5
We can solve this using a factor tree.
75
/ \
5 15
/ \
3 5