# Looking for the English term for rewriting an equation to express a variable

If I rewrite an equation

$$\sqrt{a} + b = 10$$

to

$$a = 100 - 20b + b^2,$$

how would I call that transformation to explicitly express $a$?

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Is "solving for $a$ and expanding the square using the binomial theorem" precise enough for your needs? –  t.b. May 11 '11 at 8:46
I think "solving for a" is what I was looking for. Can you make that an answer? :) –  justAnovice May 11 '11 at 8:47
One could also say you're isolating $a$. –  Ｊ. Ｍ. Jul 27 '12 at 0:33

Is "solving for $a$ and expanding the square using the binomial formula" precise enough for your needs?
Just solving for $a$, without any other transformation, would be $a = (10 - b)^2$. –  Kevin Reid May 12 '11 at 0:36