3 gallons because there are 4 quarts in a gallon and 12/4=3
<h2><u>COMBINED OPERATIONS</u></h2><h3>Exercise</h3>
First, let's solve the subtraction (in parentheses):


Now, let's solve the multiplication. Remember: in multiplication, two negative numbers will give a positive number:


Finally, let's solve the division:

<h3><u>Answer</u>: 16</h3>
Answer:
R ≈ 8.31
Step-by-step explanation:
Filling in the given values ...
... pV = nRT
... 2·4.155 = 1·R·1
... 8.31 = R
For this problem you have to isolate the variable. To do this you must inverse the operations. Multiply 18 by 5, then divide by 12 to get your answer of 7.5
1.; 3.; 5. are prime numbers.
All others are composite numbers.
Good luck!