Which of the following is a solution to the equation 5x^2-12=168? A. 6.75 B.-6 C.5 D.-5.59

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Answer 1 · 2018-05-03T00:16:59

B. #x = -6#

We are given that #5x^2 - 12 = 168#. Adding #12# to both sides yields #5x^2 = 180#. Dividing #5# from both sides gives #x^2 = 36#.

We can now take the square root of both sides, making sure to add a #pm# next to our radical. This gives #x = pm sqrt(36) = pm 6#.

Thus, our solutions are #x = 6# and #x = -6#. The latter solution corresponds to choice (B).