a)F=ma, you would divide F by a to get it onto the left side of the equation, so F/m=a. Use this as the basis for the next two problems.
b)-34/10= -3.4 units
c)If you look for m, do the same thing. F=ma, so divide by a to get it to the left side. F/m=a, so 36/12=3 units