When you're simplifying equations, you have to collect the like terms (the similar ones, eg- fractions would be like terms, and so would letters). When you're simplifying, you also have to take note of the operation before the equation. 1) Firstly, collect the like terms of M (M and -4M). As M comes before -4M, you have to add -4M to M. As -4M is a negative, this overwrites the addition, and this becomes M-4M. This then gives you -3M. The same applies to the fractions, as you have -1/6 + 5/6, you have to add 5/6 to -1/6, and this gives you 4/6, or 2/3 simplified. Therefore, you put these together- and this gives you -3M + 4/6, however, you normally have a negative number second, so one this has been rearranged, this gives you 4/6-3m.
2). Same applies to this one, you also have to collect the like terms of W. 2.3W and -3W. You simply have to subtract -3W from 2.3W, and this gives you -0.7W. You now have to collect the numbers, and you have -7 and 8. 8 is a positive, therefore, you have to add 8 to -7, giving you 1. Therefore, when you collect the like terms, this gives you -0.7W+1. As aforementioned, you cannot have a negative first, so one this is rearranged, this gives you 1-0.7W
