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Answer:
The correct answer would be [tex]a=\sqrt{c^2-b^2}[/tex]
Step-by-step explanation:
given [tex]a^2+b^2=c^2[/tex] we want to solve for a
How?
We can do this by using basic algebra ( isolating the variable (a ))
Step 1 subtract [tex]b^2[/tex] from each side
[tex]a^2+b^2-b^2=a^2\\c^2-b^2=c^2-b^2[/tex]
now we have [tex]a^2=c^2-b^2[/tex]
step 2 take the square root of each side
[tex]\sqrt{a^2} =a\\\sqrt{c^2-b^2} =\sqrt{c^2-b^2}[/tex]
we're left with [tex]a=\sqrt{c^2-b^2}[/tex]
Hence your answer is A