Question 684383
{{{y=x^2+4x}}} and 

{{{y=4x+6}}}
_____________________ solve this system; as you can see left sides are equal, so the right sides must be equal too

than we have:

{{{x^2+4x=4x+6}}}...move {{{4x}}} to the left

{{{x^2+4x-4x=6}}}

{{{x^2+cross(4x)-cross(4x)=6}}}

{{{x^2=6}}}

{{{x=sqrt(6)}}}

{{{x=2.4494897427831780981972840747059}}}

{{{x=2.45}}}

or

{{{x=-2.45}}}


now find {{{y}}}


{{{y=4x+6}}}...if  {{{x=2.45}}}

{{{y=4(2.45)+6}}}

{{{y=9.8+6}}}

{{{y=15.8}}}


{{{y=4x+6}}}...if  {{{x=-2.45}}}

{{{y=4(-2.45)+6}}}

{{{y=-9.8+6}}}

{{{y=-3.8}}}



{{{drawing(600,600,-10,10,-10,20,grid(1),circle(-2.45,-3.8,0.2),circle(2.45,15.8,0.2),graph(600,600,-10,10,-10,20,x^2+4x, 4x+6))}}}