The total length of two ships is 1841 feet. The difference in their lengths is 13 feet. Find the length of each ship.

9514 1404 393

  927 ft

  914 ft

Step-by-step explanation:

The lengths are half the sum plus or minus half the difference:

  1841/2 ± 13/2 = {1854/2, 1828/2} = {927, 914} . . . feet

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Let x represent the shorter length. Then x+13 is the longer length. Their total is ..

  x +(x +13) = 1841

  2x = 1841 -13

  x = (1841 -13)/2 . . . . half the sum minus half the difference

Then the longer length is ...

  x+13 = (1841/2) -(13/2) +13

  x +13 = (1841/2) +(13/2) . . . . half the sum plus half the difference