Hello, pashah,Originally Posted bypashah

to b): rearrange, so that the RHS of the equation is zero. Put the factor z befor the bracket. Then you have two factors. This product can be only zero if one of the factors is zero:

to c) (Are you sure that there isn't a typo? If you have +8 instead of -8 then you could use factorization) Use the formula:

to d) Use the formula:

Greetings

EB