f=f(x) reflected over the x axis is y = -f(x)
y = x reflected over x axis is y = - x
Shift down by 6 means subtract 6 outside of what's happening to x: y = -x - 6
Shift left by 5 means add 5 inside what's happening to x: y = -(x+5) - 6
Distribute: y = - x - 5 - 6
y = - x - 11