Question

Could someone answer and explain these please? Thank you!

Answer 1

Answer 1:

It is given that the positive 2 digit number is 'x' with tens digit 't' and units digit 'u'.

So the two digit number x is expressed as,

$x=(10 \times t)+(1 \times u)$

$x=10t+u$

The two digit number 'y' is obtained by reversing the digits of x.

So, $y=(10 \times u)+(1 \times t)$

$y=10u+t$

Now, the value of x-y is expressed as:

$x-y=(10t+u)-(10u+t)$

$x-y=10t+u-10u-t$

$x-y=9t-9u$

$x-y=9(t-u)$

So, $9(t-u)$ is equivalent to (x-y).

Answer 2:

It is given that the sum of infinite geometric series with first term 'a' and common ratio r<1 = $\frac{a}{1-r}$

Since, the sum of the given infinite geometric series = 200

Therefore,$\frac{a}{1-r}=200$

Since, r=0.15 (given)

$\frac{a}{1-0.15}=200$

$\frac{a}{0.85}=200$

$a=0.85 \times 200$

a=170

The nth term of geometric series is given by $ar^{n-1}$.

So, second term of the series = $ar^{2-1}$ = ar

Second term = $170 \times 0.15$

= 25.5

So, the second term of the geometric series is 25.5

Step-by-step explanation: