Given that [tex]$y=\frac{2}{1-x}$[/tex] and that [tex]$x=\frac{1}{b}$[/tex],

find an expression for [tex][tex]$y$[/tex][/tex] in terms of [tex]$b$[/tex].

Give your answer as a single fraction in its simplest form.



Answer :

To find an expression for [tex]\( y \)[/tex] in terms of [tex]\( b \)[/tex], we start with the given equations:

[tex]\[ y = \frac{2}{1 - x} \][/tex]
[tex]\[ x = \frac{1}{b} \][/tex]

First, substitute [tex]\( x \)[/tex] with [tex]\( \frac{1}{b} \)[/tex] in the expression for [tex]\( y \)[/tex]:

[tex]\[ y = \frac{2}{1 - \frac{1}{b}} \][/tex]

To simplify the denominator, let's combine terms inside the fraction:

[tex]\[ 1 - \frac{1}{b} \][/tex]

We need a common denominator to combine the terms. The common denominator is [tex]\( b \)[/tex], so we rewrite [tex]\( 1 \)[/tex] as [tex]\( \frac{b}{b} \)[/tex]:

[tex]\[ 1 - \frac{1}{b} = \frac{b}{b} - \frac{1}{b} = \frac{b - 1}{b} \][/tex]

Now, substitute this back into the expression for [tex]\( y \)[/tex]:

[tex]\[ y = \frac{2}{\frac{b - 1}{b}} \][/tex]

To divide by a fraction, we multiply by its reciprocal. The reciprocal of [tex]\( \frac{b - 1}{b} \)[/tex] is [tex]\( \frac{b}{b - 1} \)[/tex]:

[tex]\[ y = 2 \times \frac{b}{b - 1} = \frac{2b}{b - 1} \][/tex]

Thus, the expression for [tex]\( y \)[/tex] in terms of [tex]\( b \)[/tex] is:

[tex]\[ y = \frac{2b}{b - 1} \][/tex]

This is the required expression for [tex]\( y \)[/tex] in the simplest form.