#### Answer

$x = 14 ft, 3\frac{1}{2}$in

#### Work Step by Step

To find the length x, we just have you just have to subtract the "blank" pieces (the distances without the pipelines) from the total length of the pipe.
The only difference from previous exercises is the fact the you have feet and inches.
So,
x = 16 ft 4$\frac{1}{2}$in - 1 ft 2$\frac{1}{4}$in - 10$\frac{3}{4}$in
It would be better to convert everything into the same units, so you have to remember that: 1 ft = 12 inches.
=>
x = 16(12in) + 4$\frac{1}{2}$in - ( 1(12in) + 2$\frac{1}{4}$in ) - 10$\frac{3}{4}$in
We can rewrite 4$\frac{1}{2}$in as 4 in + $\frac{1}{2}$in, so doing this to all mixed fractions, we get:
x = 192 in + 4 in + $\frac{1}{2}$in - 12 in - 2 in - $\frac{1}{4}$in - 10 in - $\frac{3}{4}$in
Add all whole numbers together and used their maximum common divisor to add the fractions. In this case the m.c.d. is 4.
x = 172 in + $\frac{2(1)-1-3}{4}$in = 172 in - $\frac{1}{2}$in
So x = 171 $\frac{1}{2}$in
To convert this answer to feet-inches, just divide the whole number by 12. That is the total feet. If you get a decimal, those are the inches.
x = 14 ft $3\frac{1}{2}$in