Which of the following shows the correct first step to solve x^2-16x=-21 by completing the square? I'll give brainiest ASAP
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An expression is defined as a set of numbers, variables, and mathematical operations. The correct option is C.
In mathematics, an expression is defined as a set of numbers, variables, and mathematical operations formed according to rules dependent on the context.
The perfect square of the given expression can be created by adding 36 to the expression, then the expression will reduce to,
(x-6)² = x² - 12x + 36
Hence, the correct option is C.
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