Answer:
Step-by-step explanation:
abc = 1
We have to prove that,

We take left hand side of the given equation and solve it,

Since, abc = 1,
and c = 
By substituting these values in the expression,




Which equal to the right hand side of the equation.
Hence, 
Answer:
<h3><u>Let's</u><u> </u><u>understand the concept</u><u>:</u><u>-</u></h3>
- Here 12 is 90% of a number.
- So we can say that 90% of That number is 12 .
- In this way we can get the the number
<h3><u>Solution</u><u>:</u><u>-</u></h3>
Let,
the number=x
<h3>According to the question ,</h3>


- We know 90%=90/100
- so add it




- Now use cross multiplication method








- Answer will come in decimals so we take approximate value.




The number is 13.
We are asked to determine the present value of an annuity that is paid at the end of each period. Therefore, we need to use the formula for present value ordinary, which is:

Where:

Since the interest is compounded semi-annually this means that it is compounded 2 times a year, therefore, k = 2. Now we need to convert the interest rate into decimal form. To do that we will divide the interest rate by 100:

Now we substitute the values:

Now we solve the operations, we get:

Therefore, the present value must be $39462.50