We know that functions are mathematical entities that assign unique outputs to given inputs. In other words, a function can't have repeated values in the input repeated x-value.
For example consider the relation {(1,4), (1,5), (2,6), (3,7), (4,8), (5,9)}.
We see that above relation has repeated x-value "1" which is assigned to two different output values 4 and 5. So by definition of function, above relation can't be a function.
Answer:
<em>The number is 46</em>
Step-by-step explanation:
<u>Equations</u>
Suppose:
a = One digit of the number
b = Tens digit of the number
The sum of the digits is 10:
a + b = 10
The number expressed as two-digits quantity is ab, and its value is
10a+b
When we add 18 to that number, we have:
10a+b+18
And that is represented as the number reversed:
10a+b+18=10b+a
Simplifying:
9a+18=9b
Dividing by 9:
a + 2 = b
Substituting in the first equation:
a + a + 2 = 10
2a = 8
a = 4
b = a + 2 = 6
Thus the number is 46
Answer: (x+4)^2 -1
Step-by-step explanation:
Answer: 90% decrease
Step-by-step explanation: First determine whether the number is increasing or decreasing. Since it changes from 2,000 to 200, it's going down so it's decreasing.
Now to find the percent decrease, we divide the
amount of change by the original number.
The <em>amount of change</em> is the difference between the two numbers
which in this case is 2,000 - 200 and the original number is 2,000.
.
2,000 - 200 is 1,800.
So we're left with 1,800/2,000 and dividing
2,000 into 1,800 gives us 0.9.
Remember however that our problem is
asking for a <em>percent</em>, not a decimal.
So we need to write 0.9 as a percent and we can do
that by multiplying it by 100 and adding the percent sign.
So 0.9 becomes 90%.
So when a number changes from 2,000 to 200,
it has decreased by 90%.