The answer is 93
If we sorted out the number of each hours, the sequence will look like this
57 _ 69 _ 81 _ x _ 105
(in which x is the fourth hour of work)
We can see from the sequence that each hours, the mailman add additional 12 letters.
(69 - 57 = 12)
(81 - 69 = 12) . . . . proof
So, the amount of letters on the fourth hour would be:
81 letters + 12 letters = 93 Letters
Answer: x = 21°
Step-by-step explanation:
37 + 4x + (3x - 4) = 180° Original Equation
37 + 4x + 3x - 4 = 180° Commutative Property of Addition
7x + 33 = 180° Combine like terms
7x = 148° Subtract 33 from both sides
x = 21° Divide both sides by 7
Do you want a proof or just the answer?
The answer is: the square (2.5x2.5).