Subtract and simplify

23 ft 7 in
- 13 ft 11 in

18 gal 2 qt
- 5 gal 3 qt

21 yd 1 ft 7 in
- 12 yd 2 ft 9 in

9 ft 8 in12 gal 3 qt8 yd 1 ft 10 in

Step-by-step explanation:

There are several different ways you can work problems like this. The method you may prefer may be different from the one I prefer. At least, they include ...

You can treat the smaller units as a fraction of the larger unit: 23 7/12 -13 11/12. Then subtracting mixed numbers proceeds in any of the usual ways. You may even be able to use a calculator for this.You can "subtract by adding": 8 inches added to the subtrahend makes it 14 ft 7 in; then adding 9 ft makes it 23 ft 7 in. The difference is then seen to be 9 ft 8 in.You can subtract the different units separately, then "make change" or "borrow" as required. 23'7" -13'11" = 10'(-4)" = 9'8". (This is probably the method I prefer.) An on-line calculator may be able to handle the mixed units to your satisfaction (see attached).

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1. There are 12 inches in a foot.

  23 ft 7 in - (13 ft 11 in) = (23 -13) ft (7 -11) in = 10 ft (-4) in = 9 ft 8 in

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2. There are 4 quarts in a gallon.

  18 gal 2 qt - (5 gal 3 qt) = (18 -5) gal (2 -3) qt = 13 gal (-1) qt = 12 gal 3 qt

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3. There are 3 feet in a yard and 12 inches in a foot.

  21 yd 1 ft 7 in -(12 yd 2 ft 9 in) = (21 -12) yd (1 -2) ft (7 -9) in

  = 9 yd (-1) ft (-2 in)

  = 8 yd 2 ft (-2) in

  = 8 yd 1 ft 10 in

The answers are A, C, D.

Hope this helps.