I'm not sure what you mean by difference, so I am guessing you meant to write "distance". If this is not the case, then feel free to report me. Anyway, to find the distance between two points you would use the distance formula.
Distance Formula:
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Let's substitute our point coordinates into the formula. We'll substitute -1 and 6 for x_2 and x_1, and 14 and 16 for y_2 and y_1. After substituting, your formula will now look like:
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Subtract the coordinates.

Square the subtracted coordinates.

Add 49 and 4.

Square root 53 and round the answer to the nearest tenth.
7.28 becomes 7.3.
7.3 units is the distance between points M and Z.
There are no options given, but I will give you the exact answer of 16/60 simplified.
30 less than means -30
4 times a number means 4 times x or 4x
equal means =
14 is 14
-30+4x=14
add 30 boths ides
30-30+4x=14+30
0+4x=44
4x=44
divid by 4
4/4x=44/4
1x=11
x=11
It is 17ft because i know im in high school and the diagram show