First, we can see that he used the Distributive property. Then after that, he used the Additive property. After that, he combined like terms and the used the additive property again. Finally, he used the divisive property.
Answer:
1
Step-by-step explanation:
When multiplying fractions just multiply the numerator and denominators together, then simplify the fraction you get.
To solve the addition problem, first convert 2 and 1/2 to an improper fraction. It should be 5/2. Now 3/8 and 5/2 must be added together.
To add these, they must have the same denominator. Let's give 5/2 a denominator of 8, so it matches 3/8.
To give 5/2 a denominator of 8, you are starting with a denominator of 2. 2 × 4 = 8, so you must multiply 5/2 by 4.
You should get 20/8. Now you have to add 20/8 and 3/8. The only thing you add is the numerator, so you should get 23/8 as a final answer.
For the subtraction problem, do these same steps to make the fractions you must subtract have the same denominator, then subtract only the numerator to get the answer. Once you solve the subtraction problem, text me what you got so I can check it for you. :)
Answer:
it's probably 8.1
Step-by-step explanation:
:)
P.S: You could use a calculotor next time
Answer:
Proved
Step-by-step explanation:
From the given parameters, we have:
i.e. the length of each security numbers
i.e. 2 security numbers
Required
In 513 security numbers, 2 must have matching zeros
To do this, we make use of Pigeonhole principle.
First, we calculate the number of all security numbers not having matching zeros.
Each of the 9 digits can be selected in 2 ways.
2 ways implies that each digit is either 0 or not
So, total selection is:
Apply Pigeonhole principle
The principle states that: suppose there are n items in m containers, where 
, then there is at least one container that contains more than 1 item.
This means that if there are 512 security number without matching zeros, then there is 1 (i.e. 512 + 1) with matching zeros.
