increase decrease constant

Using my calculator I can find the answer but am having problems algebraically.

-abs(x+4)-abs(x+1)

If i take the first derivative and then set that equal to zero I get the numbers that I want.

So I get

-(x+4)/abs(x+4) - (x+1)/abs(x+1) How should I solve this. I am having a problem getting a common denominator. I do not know what to do with the absolute value signs.

Thanks for the help.

I know that x=-1.06383 and -3.829787 but I want to do this by hand and not the calculator.