<PRE><B>Question 877569</B>
Convert the mixed numbers to fractions first.
{{{17+5/8=136/8+5/8=141/8}}}
{{{9+3/4=36/4+3/4=39/4}}}
To add or subtract fractions, you need a common denominator.
Choose 8.
So,
{{{39/4=(39/4)(2/2)=78/8}}}
Now you can subtract,
{{{141/8-78/8=63/8}}}
Now convert back to a mixed number,
{{{63/8=7+7/8}}}
7 7/8</PRE>