Having trouble finding the answer

3/8 = 6/16 after multiplying top and bottom of the original fraction by 2

So the mixed number 19&3/8 is the same as 19&6/16

Subtract off 1/16 to account for the width of the saw

6/16 - 1/16 = 5/16

note how I only worried about the fraction portion. I didn't worry about the whole part 19

So after accounting for the width of the saw, we have 19&5/16 of metal left over. Now subtract off the value 11&9/16

If you line up the mixed numbers, you'll see that 5/16 is over top 9/16 when we subtract. The top fraction 5/16 is smaller than 9/16, so we have to borrow

Borrow 1 from 19 and that 19 drops to 18. Carry that 1 over to add to 5/16 and we get

1+5/16 = 16/16+5/16 = 21/16

19&5/16 turns into 18&21/16 which allows us to subtract like so

(18&21/16) - (11&9/16) = (18-11) & (21/16-9/16) = 7&12/16 = 7&3/4

So you will have 7&3/4 inches of metal left over, which is not enough to make another fixture since you need 11&9/16