Question 902881
Number 2:


Any 3x+4y=c will be a parallel line to the first equation.


The x-intercept of {{{x+2y=6}}}, is {{{x+2*0=6}}}, {{{x+0=6}}}, {{{highlight_green(x=6)}}}.
This is the point (6,0).


You want 3x+4y=c to pass through or contain point (6,0).
{{{c=3*6+4*0}}}
{{{highlight_green(c=18)}}}.


The line you are looking for is {{{highlight(3x+4y=18)}}}.



Question Number 1:
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You should study what I showed for Number 2, and then solve Number 1 yourself.
In number 2, you wanted a line parallel to another.  In Number 1 you want a line PERPENDICULAR to another.  Either use some understanding of standard form, or convert the given first equation into slope-intercept form, and identify the slope.  You want the product of the slopes to be {{{-1}}}.  for lines to be perpendicular.  Use the needed point to find the value for c in Ax+By=C, along with the needed values for A and B in the expression Ax+By.
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LESS WORDY WAY TO THINK OF THIS,
{{{3x-2y=6}}}
{{{-2y=-3x+6}}}
{{{y=(-3/-2)x+6/(-2)}}}
What is the slope?
You want to use slope of {{{m(-3/-2)=-1}}} for the line you want.
NOW, known slope m, known given point, determine what is C.