Let p = (a,b) be the point of intersection of the line y = 2x-10 and the line through (7,8) and (9,0) Compute a+b.
First, you will have to find the equation of the line between the two given points... slope, m = rise/run = 8/-2 = -4
line equation is then y = -4x +36
Now equate the two line equations
2x-10 = -4x+36 now solve this for the 'x' coordinate which is 'a'
use this value in either of the line equations to calculate the 'y' coordinate....which is 'b'
Once you have the equations for two lines, the point of intersection (a,b) satisfies both equations ....so if you equate the line equations
you can solve for the point x, which is 'a'
2x-10 = -4x+36
6x = 46
x = 46/6 = 'a' now use this value in one of the equations to calculate y (which is the 'b' value) .....then add them together to answer your Q