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Answer:
7.4
Step-by-step explanation:
solve for side a in first triangle:
[tex]10^2-6^2=y^2[/tex]
100-36=[tex]\sqrt{64}[/tex] (take square root of 64)
y=8
then use 8 to solve for x:
[tex]8^2-3^2=x^2[/tex]
64-9=[tex]\sqrt{55}[/tex] (take square root of 55)
x=7.4