Question 178815
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Line eqns:{{{system(2x+5y=4(EQN1),x+5y=7(EQN2))}}}
In EQN 2 we get,
{{{5y=7-x}}}--->{{{cross(5)y/cross(5)=(7-x)/5}}}
{{{y=7/5-(1/5)x}}}, EQN 3,subst. in EQN 1:
{{{2x+5(7/5-(1/5)x)=4}}}---->{{{2x+cross(5)*(7/cross(5))-cross(5)*(1/cross(5))x=4}}}
{{{2x+7-x=4}}}
{{{x=4-7=highlight(-3=x)}}} subst. in EQN 3:
{{{y=7/5-(1/5)(-3)=7/5+3/5=10/5}}}
{{{highlight(y=2)}}}
As we see the graph,
{{{drawing(400,400,-6,6,-6,6,grid(1),graph(400,400,-6,6,-6,6,-(2/5)x+(4/5),-(1/5)x+(7/5)),blue(circle(-3,2,.12)))}}}----->RED>>> EQN 1; GREEN EQN 2
Thank you,
Jojo</pre>