Answer :

Let's solve the given mathematical problem step-by-step.

Given:
[tex]\[ \sqrt[x]{a} = \sqrt[y]{b} = \sqrt[2]{c} \][/tex]
and
[tex]\[ a \cdot b \cdot c = 1 \][/tex]

We need to prove that [tex]\(x + y + 2 = 0\)[/tex].

First, let's introduce a common variable [tex]\(k\)[/tex] which represents [tex]\(\sqrt[x]{a} = \sqrt[y]{b} = \sqrt[2]{c}\)[/tex]. That is:
[tex]\[ \sqrt[x]{a} = \sqrt[y]{b} = \sqrt[2]{c} = k \][/tex]

From this, we can express [tex]\(a\)[/tex], [tex]\(b\)[/tex], and [tex]\(c\)[/tex] in terms of [tex]\(k\)[/tex]:
[tex]\[ a = k^x, \quad b = k^y, \quad c = k^2 \][/tex]

Now substitute these expressions into the equation [tex]\(a \cdot b \cdot c = 1\)[/tex]:
[tex]\[ k^x \cdot k^y \cdot k^2 = 1 \][/tex]

Combining the exponents, we get:
[tex]\[ k^{x + y + 2} = 1 \][/tex]

Since the base [tex]\(k\)[/tex] must be a positive real number, the only way [tex]\(k^{x + y + 2} = 1\)[/tex] can be true is if the exponent is zero. Therefore:
[tex]\[ x + y + 2 = 0 \][/tex]

Rearranging this equation, we get:
[tex]\[ x + y + 2 - 2 = 0 - 2 \][/tex]
[tex]\[ x + y = -2 \][/tex]

So, we have proven that:
[tex]\[ x + y + 2 = 0 \][/tex]

Thus, [tex]\(\boxed{x + y + 2 = 0}\)[/tex] is indeed correct.