Answer:
Step-by-step explanation:
I attached a graphic analysis that should be easier to follow.
Set up equations for the three right triangles:
x^2 + z^2 = 10^2
3^2 + y^2 = z^2
y^2 + 7^2 = x^2
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Rearrange so that we have values for x^2, y^2, and z^2:
y^2 = x^2 - 49
y^2 = z^2 - 9
x^2 - 49 = z^2 - 9
z^2 = x^2 - 40
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Now find a substitution that allows us to produce one equation with only one unknown.
Satrt with this one: x^2 + z^2 = 10^2
Then use the expression for z^2 from above (x^2 - 40):
x^2 + (x^2 - 40) = 10^2
2x^2 = 140
x^2 = 70
x = (70)^(1/2)
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