Question 1140513
Only doing 1 and 4


1:

{{{2(x+3)^2-2(x+3)+3}}}
{{{2(x^2+6x+9)-2x-6+3}}}
{{{2x^2+12x+18-2x-3}}}
{{{highlight(2x^2+10x+15)}}}


4:

Finding the intersection
{{{system(x-2y=6,4x-2y=10)}}}
{{{E2-E1}}}:
{{{3x=4}}}
{{{x=4/3}}}
-
{{{system(2x-4y=12,2x-y=5)}}}
{{{E1-E2}}}
{{{-3y=7}}}
{{{y=-7/3}}}


Parallel to {{{x+4y=12}}} contain point  ( 4/3, -7/3 ):
{{{x+4y=4/3-7/3}}}
{{{highlight(x+4y=-1)}}}