Answer:
5
Explanation:
Whenever there are problems that have ladders leaning on a buildings, you have to know that is makes a right triangle.
3^2 + (x-1)^2 = x^2
(x-1)(x-1) = x^2 - 2x + 1
9 + x^2 -2x +1 = x^2
-x^2 -x^2
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-2x +10 = 0
-10 -10
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-2x=-10
-2x/2 -10/2
x=5 (the length of the ladder)