Answer:
The number of possible three-digit phone prefixes that are used to represent a particular geographic area is 640.
Step-by-step explanation:
The phone prefixes used to represent a particular geographic area are a 3 digit code consisting of numbers from 0 to 9.
The prefix code are of the form: <u>x</u> <u>x</u> <u>x</u>
Condition: The first or the second place cannot take values 0 or 1.
Then the first place can be occupied by the remaining 8 digits.
Similarly the second place can also be occupied by the remaining 8 digits.
And the third place can be occupied by any of the 10 digits.
So the number of ways to construct a phone prefix for any area is:
Thus, the number of phone prefixes possible for any area is 640.
Answer:
x=5
Step-by-step explanation:
2(x+4)+2x+3=3x+16
One solution was found :
x = 5
Answer:
4n+1
Step-by-step explanation:
Term 1: 4(1)+1 = 5
Term 2: 4(2)+1 = 9
Term 3: 4(3)+1 = 13
Term 4: 4(4)+1 = 17
Answer:
Step-by-step explanation:
Using the parallelogram theorem
3x-8 = 10x+13
-7x = 21
x = -3
Substitute
3(-3) - 8
-17
10(-3) + 13
-17
We need to account for both x values on either side of the length, and width.
Thus, the length becomes 10 + x + x = 10 + 2x
and the width becomes 5 + x + x = 5 + 2x
For the second question, I'm assuming we don't account for the area that is covered by the garden.
Then we can say that the path is measured by: (5 + 2x)(10 + 2x) - 50, which is the area of the garden itself.
(5 + 2x)(10 + 2x) - 50 = 54
Expanding the brackets:
x = -9, or x = 3/2
Since x > 0, then x ≠ -9
Thus, the only x-value we can take is x = 3/2
