Question 1086961
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{{{x^2 + 12^2}}} = {{{(x+4)^2}}}.   (Pythagorean theorem)


Solve for x, the distance from the wall.


{{{x^2 + 144}}} = {{{x^2 + 8x + 16}}},

128 = 8x  ====>  x = {{{128/8}}} = 16.


Thus the distance from the wall = 16 ft.  Hence, the length of the ladder is 16 + 4 = 20 ft.
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