addition and multiplication principles

[fc1123]

ok I have the problem 8-7z+3z=20+5z what I have done so far is now I have the combined the like terms so far so now I have 8+5z=20+5z not sure where to go next please help.

 

[Aladdin]

ok I have the problem 8-7z+3z=20+5z what I have done so far is now I have the combined the like terms so far so now I have 8+5z=20+5z not sure where to go next please help.

Your apprach for answering this question was correct , getting like terms ~~ But what you got is wrong .

$\displaystyle 8-7z+3z=20+5z$

$\displaystyle 8-4z=20+5z$

$\displaystyle -4z-5z=20-8$

$\displaystyle -9z=12$

$\displaystyle z= ?? mmmmm$