where would you start with this sum 10-4x2+6 divided by 3 =

Start with the multiplication in the numerator.  Your expression is ambiguous with regard to the division. 

 

If you mean (10 - 4*2+6)/3, then continue to evaluate the numerator and divide the result by 3.

 

However, if you mean 10 - 4*2 +(6/3), then continue by dividing the 6 by 3, then evaluate the rest.

.