Hello.
What to explain here? Please tell how you are calculating this question, step by step. After that we will tell you where you are wrong.

I've tried numerous ways and I can't get the answer 42. If someone could show me their working out I can see where I went wrong . Thanks

By basic rules of math first you must calculate what is in inner brackets. After that you must calculate what is in outer brackets. Remember what multiplication and division has priority over addition and subtraction.
-3 [8 - 3 (5 + √9) - ( 7 - 9)] =
-3 [8 - 3 * 8 - (-2)] =
-3 [8 - 24 + 2] =
-3 * (-14) = 42

Thanks I got to -3 [8 - 24 + 2] but was basically doing -3 [8 - (24 + 2)] = -3*(-18)
I understand now cheers for the help

You welcome.
You can buy a Training DVD. There is all materials what you need to rise up your math skill, and other modules too of course. :)

42

How do we get -14?
following BODMAS, I get 24 + 2 = 26 and 8 - 16 = -18.

Is anyone else seeing this???:

-3 [8 - 3 (5 + and#8730;9) - ( 7 - 9)] =

Hey andyrhcp104, there was issue with encoding, now it is fixed.

Thanks Dimky