Find the midpoint of the two intersection points of the graphs 2x-3y=7 and (x-6y)^2+9(3y-2)=-5.
I could not understand the following method...
Let the two intersection points be (X1, Y1) and (X2, Y2).
Then X1+X2=22/3 and they work out Y1+Y2 using the value of X1+X2 and finally divide by 2 to get the midpoint.
My question is how to get X1+X2=22/3?
Your help will be much appreciated!
Well, you can get X1+ X2 by first getting X1 and X2! Those are the x coordinates of the points where 2x- 3y= 7 and . Since it is x you ask about, solve the first equation for so . Then and . So which then gives the quadratic equation or . Solve that the two values of x or, more simply, recall that if and are the two solutions of then which, here, is .