A reflection across the x-axis means that for every x value, the y value is the opposite of what it would be in the original function.
f(x) = x + 6
What is the equation for the reflection across the x-axis? since the y-value is the opposite of its normal value at every point, g(x) = -f(x)
g(x) = -f(x)
g(x) = -(x+6)
g(x) = -x - 6
Third choice is the answer
