Question 1000892
Only giving help for two of them.


#2:

No use of h is shown.
{{{m=(2k-k)/(1-0)=k/1=k}}}, just using the formula for slope.
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{{{y=mx+c}}}
{{{y-mx=c}}}
{{{c=y-mx}}}.... but if you know about slope intercept form, you can identify the given   (0,k)  as the y intercept, so the equation is  {{{y=kx+k}}}.


#4:

See this video example showing how to do this...
<a href="https://www.youtube.com/watch?v=VDKztVZUgnM">Equation of line through two given points - example</a>