Question 165846
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Line equations ---{{{system(y=-4x+7,12x+3y=21)}}}
1st eqn, it follows slope intercept form {{{y=mx+b}}} ---> working eqn
slop;{{{-4}}} & y intercept; {{{7}}}
f(y)=0 ---> {{{-7=-4x}}}---> {{{-7/-4=cross(-4)x/cross(-4)}}}
{{{x=7/4}}}
2nd eqn,via working eqn:
{{{12x+3y=21}}}
{{{y=(21-12x)/3}}} ----> {{{y=(21/3)-(12x/3)}}}
{{{y=-4x+7}}} ----> same as 1st eqn! y-intercept @ 7
f(y)=0 ---> {{{x=7/4}}}
We'll see the graph:
{{{drawing(300,300,-5,5,-10,10,grid(1),graph(300,300,-5,5,-10,10,-4x+7,-4x+7),circle(7/4,0,.15),circle(0,7,.15))}}} -- 2 identical lines of the same eqn; points(7/4,7)
Thank you,
Jojo</pre>