Question 128035
These are all done by the same methods.  Solve for whatever means get the 'whatever' on one side of the equation, generally the left, and everything else on the other side.


{{{y = mx+b}}}, solve for {{{b}}}


Add -b to both sides:
{{{y-b=mx}}}


Add -y to both sides:
{{{-b=-y+mx}}}


Multiply both sides by -1:
{{{b=y-mx}}}


Done.


You should be able to do the others using the same technique.