Question

the line passing through (7,y) and (1,0) is parallel to the joining line (4,4) and (-2,1) find y

Answer 1

The slope of the line passing through the two given points is 6/3 = 2

Your line with the unknown y must have the same slope. Therefore
(7-1)/(y-0) = 6/y = 2
y = 3