The given expression is
[tex]\frac{(\frac{2}{a}+\frac{7}{b})}{b}[/tex]
To add 2 fractions we have to give them the same denominators
In the up part (numerator) we have 2 different denominators a and b
Then the common denominator of the 2 fractions must be the product of them
[tex]\frac{2}{a}+\frac{7}{b}=\frac{2b}{ab}+\frac{7a}{ab}=\frac{2b+7a}{ab}[/tex]
Then the fraction will be
[tex]\frac{\frac{2b+7a}{ab}}{b}[/tex]
Now, we will multiply the denominator of up by the denominator of the first fraction (ab x b)
[tex]\frac{\frac{2b+7a}{ab}}{b}=\frac{2b+7a}{b(ab)}[/tex]
Multiply b by b to simplify, then
[tex]\frac{2b+7a}{b(ab)}=\frac{2b+7a}{ab^2}[/tex]
The numerator is 2b + 7a
The denominator is ab^2