Question 1073402
{{{2x^2-4x+1=2x+21}}} will give the x coordinates of the intersection points.

{{{(x+2)(x-5)=0}}}

x coordiantes -2 and 5.


{{{y=2x+21}}}
If x is -2, then point  (-2,17)
If x is 5, then point (5,31).



DISTANCE BETWEEN (-2,17) and (5,31):
{{{sqrt((5-(-2))^2+(31-17)^2)}}}------evaluate this.
-
{{{sqrt(49+14^2)}}}
{{{sqrt(49+196)}}}
{{{sqrt(245)}}}
{{{7sqrt(5)}}}