Question 1199484
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the sum of x and z translates to x+z
the difference of z and x means we have z-x


The product of those two lines is the multiplication of each
(x+z)*(z-x)
(z+x)*(z-x)
z^2-x^2


We have a difference of squares. 
The pythagorean theorem deals with squared numbers.
a^2+b^c = c^2
x^2+y^2 = z^2
y^2 = z^2-x^2


Answer: <font color=red>y^2</font>
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